# Lionel Electronic Reverse Unit



## rrswede (Jan 6, 2012)

The Lionel motor with electronic reverse unit in the attached photo was included in a recent bulk used parts purchase. 

I am not familiar with can motors or electronic components but believe the reversing unit converts AC to DC as well as provides F-N-R operation of the locomotive. Looking through some online documentation, it appears this motor was used by Lionel in a great number of 8600 series locomotives with smoke units and was wired to a small switch to lock the motor in F, N, or R and was also wired to the tender.

In its present state, there is no smoke unit, no switch, note the nipped off wire sticking straight up in the photo that should go to the tender, and the motor cycles F-N-F-N, etc. It does not reverse. 

I would like to learn if the current operation of the locomotive F-N-F-N, etc. is the result of a faulty electronic reversing unit or some other factor. Also, if the current operation is the result of a faulty reversing unit, what component in the reversing unit would most likely create this operating condition?

Thank you, swede


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## T-Man (May 16, 2008)

First, we are talking about a 15 buck part If you want more than forward replace it. I just never got into how it works. One person did build one but his diagram wasn't readable. The chip was programmed and not off the shelf workable. Unless you want spend a lot of time on it. Go for it. I have not searched for a circuit recently so maybe we can get lucky if some one knows.


It is an interesting piece to learn more about.


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## rrswede (Jan 6, 2012)

Thanks for responding T-man.

Yes, a forward running motor is better than a dead one and, yes, a replacement could be purchased. In reality, however, I enjoy tinkering and learning in the process. If I was sure the reversing unit was faulty, knew what component(s) failed and how failure affected the cycle sequence, I'd be tempted to try to make repairs. 

swede


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## T-Man (May 16, 2008)

Maybe with a meter you can figure out if one of the t120 cases is bad. (The black three pole pieces)


WIth an id number maybe you could find the data sheet on those four pieces.


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## Norton (Nov 5, 2015)

Can you take a close up picture of both sides of the circuit board and also what is printed on the 14 Pin DIP?
I suspect someone may have altered the wiring and taken the lockout switch out of the circuit. Else something is bad on the chip, likely a flip flop of some sort. Or a bad capacitor. A cap is used to hold the DC power to the chip for 4-5 seconds after you reduce power to change direction. If the cap doesn't hold power then the chip starts in a state that moves the engine forward all the time instead of changing state (flips).

Pete


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## rrswede (Jan 6, 2012)

Thanks T-man and Norton for the responses.

Norton, when I get back home this afternoon, I will take a closeup photo and see if I can read what is printed.

For sure someone has either tampered with the switch wiring or there never was a switch. The two prongs on the board are present but if I remember correctly, it didn't look like wires had ever been connected to them.

Although the documentation I reviewed indicated the circuitry would reset to restart in forward after a period of idleness, it did not indicate that was the result of the capacitor being fully discharged, but I understand the purpose of the capacitor.

If the capacitor is not holding power would you expect the unit to flip F-N-F-N-F-N, etc., instead of F-F-F-F-F, etc.? 

Thank you, swede. Will post again in a about 4 hours


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## rrswede (Jan 6, 2012)

Enclosed is a photo of the reversing unit. 

The board is # 00-0103-00, the 14 pin DP is HCF4013BE BB405Y.

In the upper right corner you can see the two prongs that would normally be wire connected to the locking switch

swede


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## Norton (Nov 5, 2015)

As expected the HCF4013 is a dual flip flop. Most likely it drives the two small transistors (??) which drive a pair of the large devices, transistors??. 
You can google HCF4013 along with the numbers found on the two smaller TO92 and larger TO 220 devices. 

I did find an identical board. It has two wires not shown in your picture. If you look in the upper right corner using this pic as a reference you will see two points labled W5 and W6. I can see the holes in the pic. These are likely for the lockout switch. Check to see if they have been shorted out from the circuit side. If not replace the wires and short them together to see if it now reverses.









Pete


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## rrswede (Jan 6, 2012)

Thanks Norton. 

Yes, W5 and W6 are the connections for the switch. When a jumper is placed between W5 and W6, the motor operates F-F-F-F, etc. With the jumper removed, it operates F-N-F-N-F-N, etc. I'm not sure what that means.

If you think one or more of the three sets of components you mentioned could cause the unit to function as it does, I'd be tempted to purchase replacements for all and give a rebuild a try. Cost would be about $7.00 coming from China. Of course delivery could be as late as the end of July.

swede


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## T-Man (May 16, 2008)

Connecting the w5 and w6 the connection stops the cycling. I found two boards, both have been replaced because of a faulty direction. The TO 92s are A33's


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## Norton (Nov 5, 2015)

For some reason some of our posts have gone missing. Lionel has the board for 18 bucks. You don't have to send to china for the components if you want to try and repair it. Digikey will have the parts. By googling the part numbers you can download the data sheets to get the pin outs. I suspect the problem may be related to the output of the 4013 or one of the small transistors. If you put a voltmeter between common (black wire) and the transistor bases that will tell you if the base is going high to low and back or not. If its getting a signal then the problem is the transistor or after it. If its not changing state then the problem is the flip flop or something before the transistor.

Pete


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## rrswede (Jan 6, 2012)

Thanks, T-man and Norton. I was able to verify the actual part numbers for the three components off the actual board and, as indicated in another post, all of the parts, including shipping are available for about $7.00. I don't care how long it takes to get the parts. This is just a "fun" thing.

Before buying anything, I will do some checking with my meter to see if I can detect which specific part(s) may be faulty.

swede


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## Norton (Nov 5, 2015)

It may just be a bad solder joint. For the flip flop to change state the power goes through a number of passive components before it gets there. Typically the "Q" outputs are used to drive something down the line. I would start by checking these to see if they change state or not. You may have to reverse engineer the board to find the problem. It may not be as simple as swapping out active devices.

Pete


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## rrswede (Jan 6, 2012)

Thank you Norton. Much appreciated. 

Troubleshooting and repairing electronic devices are not my cup of tea as I don't have a good understanding of the terminology used or know what certain components are supposed to accomplish in the circuit. That said, if I cannot easily troubleshoot a electronic device or simply replace some inexpensive presumed defective parts, I'm usually better off replacing the unit or use the services of a trained technician. In this case, however, a fully functioning motor is not worth much and this one is worth less so I will tinker/troubleshoot a bit more before throwing in the towel.

Will be back to report the results.

Thank you, again,

swede


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## rrswede (Jan 6, 2012)

Norton, the pest is already back.

With the transformer set at 10 VAC, the lock switch open and the locomotive in neutral, should I expect to read 10 VAC across pins 7 and 14 (VDD and VSS)? 

Can you tell me how to check the Q outputs? Do I check Q1, Q1(with line over the Q), Q2 and Q2 (with line over the Q)?

Thank you once again,

swede


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## T-Man (May 16, 2008)

Don't you have a running one to compare to?

Operation is 3 to 20 volts DC The texas instrument data sheet has a lot of info.
Q with a line is the inverted reading of Q So if Q is 7 volts Q with a line is -7 volts . I am not positive? but confident.

The output is in Zeros and ones I could be wrong.


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## T-Man (May 16, 2008)

If you check the chip first and if it is the point of failure I would suggest using a 14 pin connector. That way you just solder the connector and replace the chip. I did check the engine and there is clearance for the connector.


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## highvoltage (Apr 6, 2014)

Not adding anything to the repair portion of this thread, but I'm curious why they added a neutral in an electronic reversing circuit. Maybe it's nostalgia for the old rotating drum reversing units that went F-N-R-N? Today's Legacy diesels flip back and forth between forward and reverse, which mimics real operation, I think, since I've never been on a modern diesel locomotive.


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## Scotie (Sep 27, 2013)

The N position let you operate accessories such as the milk car when they are wired to track power. It was fairly recently that folks wired them to a separate power supply. When I was a kid I had a 1033 transformer, no accessory outputs.


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## DennyM (Jan 3, 2016)

After reading this thread I knew I should have taken some electronics classes at DeVry. I have no idea what you guys are talking about. :dunno: I will learn it though.


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## T-Man (May 16, 2008)

I started to follow through on the problem . Well you need to identify the parts. I knew the 14 pin chip was a logic or programmed. The numbers on mine didn't match up with anything until rrswede said they are Cd4013 flip flip flop. 

Now the data sheet comes in and identifies the 14 pins. A starting point on understanding how it works. The board has two small transistors in a T0-92 case ( each board I have has two different numbers A13 and A33. rrswede did not say what his numbers were for the parts. I am working on identifying the connections between the Transistors and the chip
.


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## rrswede (Jan 6, 2012)

T-man, my apologies for not getting back to you sooner.

No, I do not have another unit to compare to. That would have been very helpful.

I had glanced at the Texas Instrument site after Norton had requested the part information and printed out the pin configuration to use in troubleshooting.

Thanks for the +/-help and for indicating the output from the Qs is binary code not voltage.

In your last post, you used the term "chip". Are you referring to the two internal sections of the 4013, the entire 4013, or something else? I am guessing the entire 4013.

Before trying to respond to your previous post, I attempted to follow up on Norton's suggestion to check the Q outputs for a change in state. I presumed that meant a change in state when power is interrupted to initiate a cycle change from F to N, etc. 

I didn't know how to make that check, but with the motor running, I attempted to place one probe of my multimeter on Q1, with the other probe grounded and, with my third hand, I toggled the power interrupt on the transformer and also kept an eye on the meter. I was going to try doing that using the VDC, VAC and Resistance settings on the meter. I failed and got scared I'd fry something, so quit.

Now, to provide some input to your last post, T-man, there are three small transistors, two that are in the open and one nestled in with the capacitors. The two in the open read AMPS A13 4C and, as best I can tell, the third one reads the same. 

There are 2 ea 68K, 2 ea 22k, 2 ea 10k and 1 ea 220k ohm resistors. 

There are 5 ea blue capacitors: 1 ea 4.7 mf 35V, 3 ea 1 mf 50V and 1 ea 100 mf 25v.

There are 4 large transistors. 2 ea are TIP31A 4C and 2 ea TIP32A 4D.

If you would like me to try to identify the balance of part on the board, let me know. 

I think I'll quit for the night and take another look tomorrow.

Thanks to all, swede


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## Norton (Nov 5, 2015)

The Q outputs should be checked with the multimeter set to DC volts. It should change from close to zero volts to some higher voltage like 3-12 volts depending how they established VCC or the nominal power supply voltage. It should change for F-N-R either zero or high. Keep in mind there are many ways to wire a dual 4013 to do this. They may only be using one gate and the Q and Q not pins or both gates Q1 and Q2. The other pins like D also may come into play.
If I were doing this alone I would solder small wires to the Various pins I wanted to check. That because as you found out you need a third or fourth hand to control the transformer. There are tools to aid in this that clip onto the chip (the whole 4013) and grabber test leads which eliminate the need to solder wires but you could buy a couple of boards for what these cost.

Pete


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## rkenney (Aug 10, 2013)

Interesting thread. 

This is a fairly common motor control circuit called an 'H Bridge'

Additional circuitry to trigger (logic) the bridge and filter out spurious signals that might accidentally trigger it, etc.

Click the link above for an explanation of how the basic bridge works with some example circuits.

Tip31, 32 transistors deliver the current to actually power the motor.


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## gunrunnerjohn (Nov 10, 2010)

My experience with these is the driver transistors are frequently the source of failures, they're common and cheap.


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## tjcruiser (Jan 10, 2010)

I'm with Denny on this one ... having fun watching this with my popcorn in hand, but a bit perplexed with all of the capacitor/flip-flop/transistor jargon.

Good detective dialog, guys. Over my head, but I'm enjoying the diagnosis chat!

Cheers,

TJ


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## Norton (Nov 5, 2015)

In case you hit a road block, these can still be had.










Pete


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## highvoltage (Apr 6, 2014)

Scotie said:


> The N position let you operate accessories such as the milk car when they are wired to track power. It was fairly recently that folks wired them to a separate power supply. When I was a kid I had a 1033 transformer, no accessory outputs.


I looked up a 1033 and it has four posts: U, A, B, and C. Across A-B was fixed 5 volts; B-C = 11V, A-C = 16V. Variable voltages were achieved from B-U = 0-11V, or A-U = 5-16 V.

So it looks like accessories could be attached across A-B, B-C, or A-C depending on the fixed voltage desired?

I apologize for hijacking this thread.


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## T-Man (May 16, 2008)

Don't worry about it high voltage.


One good thing about frying something is that you know it is bad. So that is a good thing. The q outputs are DC voltage either zero or I would guess three volts, So Bob is straight on there. John talked about driver transistors so I am assuming they are the two TO 92 case transistors.

RRsuede I know about the third transistor . Just looking at all the parts I think this guy does the signal for f-n-r-n directions. Time will tell But our problem is the loss of one direction. 


For now I want to identify parts for the loyal readers.














The chip is a 14 pin CD 4013 dual flip flop.
The two TO 92 case transistors are Darlington NPN 
Four switching diodes are attached to pins 1 to 4 on the CD4013 chip. The TO 220 case transistors are back to back. Shown are TIP32c PNP transistors behind are power amplifier transistors CSD 880 NPN .



The DC motor is connected with a red and black wire to each CSD 880 on the center post the collector. Also that connection goes to the other transistor The TIP32c center post the collector


Think about that.


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## rrswede (Jan 6, 2012)

Ok, finally have time to respond to the latest posts. Thank you, Norton, hivoltage, TJ, GRJ and rkenney.

After the first couple posts by Norton and T-man, I placed orders for the small and big transistors as well as for the 4013. That and the facts that the orders are for far more of each item than I need with the total cost for all including shipment just over $7.00 make for good news. Since the parts are coming from China, delivery won't be until mid July and that's the bad news. That doesn't really bother me since there is no rush to get this motor running properly. 

GRJ's comment about his experience makes me think I could have spent a grand total of $2.00 to repair this board with lots of transistors left over. We'll see. 

For now, Norton, I'll forego the additional steps you outlined for better testing and wait for the parts to arrive. Hopefully a defective transistor shows up on the first swap out.

As usual, when seeking assistance for an issue beyond my understanding, generous members of this forum are there to provide aid and I come away with some new knowledge and greater appreciation of this forum. 

Thank you and I'll provide an update in about a month.

swede


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## T-Man (May 16, 2008)

I tested the switch diodes on pins 1 thru 4 on the Cd4013 chip.
The meter set on diode, the red away from the chip and the black next to the chip reads 700 indicating a good diode and 1 if the wires are reversed.


This means that a signal goes only to the chip and not out? I am not sure that makes sense.


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## rrswede (Jan 6, 2012)

T-man, your last 2 posts had to have appeared while I was composing mine.

Thank you for all the additional information you have provided pertaining to your test results and component identification. 

Part of your text with the photos confused me for a bit, specifically the mention of CSD 880 NPN power amplifier transistors. 

" Shown are TIP32c PNP transistors behind are power amplifier transistors CSD 880 NPN .

The DC motor is connected with a red and black wire to each CSD 880 on the center post the collector. Also that connection goes to the other transistor The TIP32c center post the collector

Think about that."


The photo in my post #7 shows two pair of TIP transistors back to back. The two on the right side are TIP32A 4D and the two on the left side, back to back with the two on the right side are TIP31A 4C. Different parts doing the same thing?


As for "thinking about that", the fact that the TO-92 transistors are drivers, if I understand GRJ correctly, leads me to think that if one has failed, the power amplifier transistors inline with that transistor are idled. If that causes the motor to cycle as it does, then it reinforces the idea that the failure is with one of the TO-90 transistors, correct, or wrong?

Thanks, T-man

swede


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## T-Man (May 16, 2008)

I wanted to make sure the parts are the same. Both of mine are not exact for parts but they are similar. From the numbers you gave me for the TO 220 case transistors, one is NPN and the other is PNP.

The driver theory is right on. Your set up can't be that different. After all it still powers the motor and they have the same part number too.


Just remember "Forward" only matters on how the wires are connected to the motor. But it appears one side is bad but they are intertwined. The bases are connected to the chip but more on that later.


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## highvoltage (Apr 6, 2014)

Swede and T-Man,

On a whim I Googled the part number Swede posted earlier (00-0103-00) and found this .pdf.  A Mr. Paul Romsky reverse engineered the board and did a complete write-up. I've attached the .pdf for your perusal. It might go a long ways towards answering some of your questions.

View attachment Lionel_E_Unit_Theory_Of_Operation.pdf


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## rkenney (Aug 10, 2013)

Great find, good article explains the E-unit well.:smilie_daumenpos:


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## Norton (Nov 5, 2015)

Thats quite a piece of work! Not only the reverse engineering but the comprehensive write up.
I wonder if Paul has any Legacy engines. I'd like to see a similar write up on Lionel's RCMC board.

Thanks for posting this High V.

Pete


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## gunrunnerjohn2 (Dec 15, 2013)

As Pete notes, there are no programmable parts on this board, all the parts are cheap generic stuff.

Again, top suspect for no motor drive is the TO-220 transistors.


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## rrswede (Jan 6, 2012)

highvoltage, thank you. That was a great find and I wholeheartedly echo Norton's response. 

GRJ, in post #25, you indicated the driver transistors are frequently the source of failures. I took that to mean the Darlington TO-92 transistors that are also referred to as driver transistors in Paul Romsky's document, not the TO-220 transistors that have been described as power amplifier transistors in this thread and simply power transistors in Rommsky's document. Was I mistaken to think you originally meant TO-92 transistors?

Thanks, swede


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## gunrunnerjohn (Nov 10, 2010)

The To-220 transistors are the actual motor drivers, the To-92 "driver" transistors are most likely used to drive the TO-220 motor drivers. I really did mean the motor driver transistors, though obviously other components can fail. However, the motor driver transistors are typically the ones that suffer if you have a motor stall or overload the motor outputs in some way.


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## wvgca (Jan 21, 2013)

i know that I have the Tip 31/32 transistors in stock, do you want two of each ??


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## Norton (Nov 5, 2015)

The transistors are easy enough to check without power. Not sure a failed output would produce F-N-F-N-F-N. I would expect failed output to look more like F-N-N-N-F with the extra neutral due to dead driver or output transistors.

Pete


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## highvoltage (Apr 6, 2014)

rrswede said:


> highvoltage, thank you. That was a great find and I wholeheartedly echo Norton's response.
> 
> GRJ, in post #25, you indicated the driver transistors are frequently the source of failures. I took that to mean the Darlington TO-92 transistors that are also referred to as driver transistors in Paul Romsky's document, not the TO-220 transistors that have been described as power amplifier transistors in this thread and simply power transistors in Rommsky's document. Was I mistaken to think you originally meant TO-92 transistors?
> 
> Thanks, swede


You're welcome. I stumbled across it but was surprised at how well it documented the board in question.

To clarify, a TO-220 is a case size, as is TO-92 (TO stands for Transistor Outline). Q1, Q2, Q3, and Q4 are power transistors; part #TIP31 (for Q1 and Q2) and part #TIP32 (for Q3 and Q4) in a TO-220 case size.

rkenney pointed out that Q1, Q2, Q3, and Q4 handle the current to the motor and could be the cause of the reverse feature not working. They are sometimes referred to as drivers, since they "drive" current. P. Romsky however refers to Q6 and Q7 as drivers, Q6 is the reverse driver and Q7 is the forward driver. Q6 and Q7 are Darlington pair transistors (part #MPSA13), in a TO-93 case size package.

I'm inferring from your posts that this is a learning project for you, basic circuit theory and repair. However, as others are pointing out, don't get too deep in parts that you exceed the replacement cost of the board. I priced the equivalent replacement part and it's only $18.00.

I see others have posted since I started writing this, but I'll post anyway as it might have clarifying information that others can use.


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## Norton (Nov 5, 2015)

I just did a very quick test on my unit which works. Putting a voltmeter on each base of the TO92s produces one high (~5V DC) followed by 3 lows (~.45v DC) as expected. Both do this but the highs alternate between the two small transistors. This with the Lockout leads open.
The Q1 and Q2 outputs do NOT follow the TO92 bases. I did not try and trace the signal back from the TO92s to see what drives them but its not the Q outputs. Maybe later.
As noted in Paul's paper, once power is applied to the board, VDD (Pin 14) is there for many minutes after power is turned off. I was surprised.


Pete


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## T-Man (May 16, 2008)

Wow highvoltage that is fantastic!
Great find!:appl::appl::appl:

I will say thanks to you all for input. :thumbsup:

I will say that both boards I have are marked off for components and I have a F-n-n-n cycle. They have slightly different resistors and The CSD 880 instead of the TIP 31. I am sure that I do have a working board with the two TIP 31 and 32 versions......somewhere?

Time to read up.


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## rrswede (Jan 6, 2012)

Have been trying to get some time since this AM to respond to the latest posts.

Thanks for the latest posts GRJ, Warren, Norton, highvoltage and T-Man and a belated thanks to rkenney.

The clarification and added information regarding TO-92 and TO-200 was appreciated GRJ. Thanks. 

Warren, thank you for the offer. When I placed my parts order to China, I included two each of TIP 31 and 32 transistors. Hopefully I won't need more.

Highvoltage, thanks for the additional information and comments. You are correct in thinking this repair effort is a learning experience for me. My time is my time and I don't put a cost to it. I'm out less than half the cost of a replacement board for way more parts than I should need and would not have considered buying a replacement. Tinkering in general and exploring new tinkering areas are part of my enjoyment schedule.

T-Man and Norton, thanks for being in this discussion from the start. When the thread was started, I expected someone to suggest replacing x with such and such part number. Wow, big mistake, and then to receive highvoltage's post. Fantastic.

Norton, in your last post, I am assuming your tests were done with the motor engaged and no readings were taken with the motor in neutral. Correct??

I did the tests as follows.

A) Motor in forward, 8VAC applied, lead 1 to ground, lead 2 to base of T93 #1, result ~2.7VDC
B) Motor in forward, 8VAC applied, lead 1 to ground, lead 2 to base of T93 #2, result ~.48VDC
C) Motor in neutral, 8VAC applied, lead 1 to ground, lead 2 to base of T93 #1, result ~2.2VDC
D) Motor in neutral, 8 VAC applied, lead 1 to ground, lead 2 to base of T93 #2, result ~2.2VDC
E) Motor should have switched to reverse but went to forward, 8VAC applied, lead 1 to ground, lead 2 to base of T93 #1, result ~2.7VDC
F) Motor should have switched to reverse but went to forward, 8VAC applied, lead 1 to ground, lead 2 to base of T93 #2, result ~48VDC

T-Man, your last post indicates F-n-n-n cycle. Typo? F-n-R-n cycle?

Thanks, swede


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## T-Man (May 16, 2008)

They are broken with no reverse.


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## rrswede (Jan 6, 2012)

T-Man, got it.

swede


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## Norton (Nov 5, 2015)

Swede I assume F-N-N-N refers to the voltage the base of each small transistor. Say its starts forward at the first application of power (F). Next cycle is neutral so voltage at the base will be low (first N), next cycle should be reverse so voltage to the first small transistor base is still low (second N), last cycle its back to neutral so this is the last N. While the first transistor is high, low, low, low, the second transitor base will be low, low, high, low (N-N-R-N). This when its working right. 
With power off you can just check the transistor leads with an ohmmeter. You can use ohms scale or if your meter has a diode symbol use that position. Put one lead on the base and the other to the others one at a time. In one position it will read some constant like 550 or close to infinity. Reverse the leads and do the same thing. If you got infinity the first time you should get 550 this time. If you get something in this ball park your transistors are likely OK. There are other varibles and sometimes this test only works with the transistors removed due to nearby components contributing to the readings but this is a first step. If you see numbers in low double digits or infinity in both directions the transistors might be toast.


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## tjcruiser (Jan 10, 2010)

highvoltage said:


> Swede and T-Man,
> 
> On a whim I Googled the part number Swede posted earlier (00-0103-00) and found this .pdf. A Mr. Paul Romsky reverse engineered the board and did a complete write-up. I've attached the .pdf for your perusal. It might go a long ways towards answering some of your questions.
> 
> View attachment 456892


Jeez! Good thing Paul Romsky is not working for the Chinese. I'd fear all of our tech secrets would be in jeopardy! 

Great find, Highvoltage. The techno-speak is way over my head, but what a treat to know that there are people out there (here at MTF there at Romsky and friends) who enjoy delving into stuff like this.

Well done!

TJ


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## highvoltage (Apr 6, 2014)

Thanks all. I hope it's helping in Swede's dissection of the circuit and troubleshooting efforts.

Swede,

Do me a favor and measure the output of Pin 1 of CD4013 as you cycle through F-N-(should be reverse)-N. Let me know what you get.

Tom


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## Norton (Nov 5, 2015)

Tom, pin 1, aka Q1, does not follow either of the small driver transistors. Mine goes, low, low, high, high. The first high occurs AFTER turning power off after the second low and stays high for two cycles.

Concurrently the motor is running F-N-R-N

Pete


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## rrswede (Jan 6, 2012)

Have attached a scan depicting results of three different tests performed on my board. In all powered tests, the transformer was set to 8 VAC and in all cases, the lock switch pins were not connected.

The first shows the results of a second test performed to respond to Norton's post #43. When the unit should be in reverse, it remains in forward. Output from the base of transistor 1 remains at 4.5 VDC for all cycle positions. Transistor two responds like I think it should.

The second shows the results of a test performed to respond to Norton's post #48. I had to set the meter at 2000K to get any readings. With the common lead attached to the base of each transistor, resistance was infinite to the collector and the emitter on both transistors. Switching leads resistance was infinite to the emitter and, for practical means, infinite at ~1900 to the collector.

The third shows the results of a test performed to respond to hivoltage's post #50. 

swede


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## Norton (Nov 5, 2015)

Swede, I think the two small transistors are OK. I think if you had a diode range on your multimeter you would have got something on both transistors to both leads when the positive probe was on the base rather than 1900 and inf. It should read inf when the negative probe was on the base. The fact that you get 4.5V on one base all the time points to something upstream. Either between the TO92s and 4013 dual flip flop, the 4013 itself, or some component attached to it.
Try the test the High V suggested and see whats going on on pin 1 of the 4013. I got two lows followed by two highs as I cycled the transformer.
BTW regarding the ohmmeter test, if the TO92s were common bipolar NPNs you would have read about same number between the two leads. Since this is a Darlington you should get one number roughly twice the other. 


Pete


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## Norton (Nov 5, 2015)

BTW you can do the ohmmeter test on the power transistors too. GRJ thinks these could be the problem so check them to be sure.

This data sheet will work for one.

https://www.mouser.com/ds/2/149/KSD880-889371.pdf

This for the other:

https://www.mouser.com/datasheet/2/308/TIP32C-1121760.pdf

Pete


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## rrswede (Jan 6, 2012)

Thanks for the responses, Norton. 

The test results for hivoltage's request were item three in my scan. Regardless of the transformer cycle position, F-N-R*-N, the voltage remained the same, 3.4 VDC, where * indicated the motor continued to run forward, not reverse.

As for testing the TO-220 resistors, I had to place the meter on the 2000K range to get any readings. Base to emitter or base to collector on both 32A transistors read ~1800 whereas all readings on the two 31A transistors were infinite.

swede


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## Norton (Nov 5, 2015)

The circuitry around 4013 is suspect. It should be toggling. Before simply swapping out the 4013 resolder all points under the board. Not sure its worth the shipping cost at this point but it might be worth installing a 14 pin socket for 4013 for future service. I think that was pointed out before but given you are homing in on the problem it may be worth it. If there is a Radio Shack or electronics parts place near you it would be worth it. 

Pete


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## rrswede (Jan 6, 2012)

Norton, just finished checking each pin on the 4013 to make sure no connections to the board had come loose. All pins top to bottom of board indicated continuity. Am about ready to set this motor aside an pull it out again when the parts arrive.

swede


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## highvoltage (Apr 6, 2014)

Norton said:


> The circuitry around 4013 is suspect. It should be toggling...


Or 4013 itself is suspect, unless Pin 1 is being held high by a device downstream.


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## highvoltage (Apr 6, 2014)

highvoltage said:


> Or 4013 itself is suspect, unless Pin 1 is being held high by a device downstream.


I've been thinking more about this.

Swede,

If you get a chance please do something for me. Lift the leg of the diode shown in the picture below. Hit it with your soldering iron and grab it with a pair of needle nose pliers. It will pull out of the board once solder starts to flow.









Removing this leg of the diode will isolate the REV output of the state machine from any downstream devices. Then take voltage readings like you did before on Pin 1 of CD4013 .


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## rrswede (Jan 6, 2012)

Hivoltage, with the upper leg of the diode pulled out of the board I redid the test.

With the leg removed and 8 VAC applied, the motor did not operate at all. I checked the voltage at pin 1 and got 3.4 VDC, the next cycle got 2.6, the next was 3.4, again, the next was 2.6, again, etc. etc.

swede


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## highvoltage (Apr 6, 2014)

rrswede said:


> Hivoltage, with the upper leg of the diode pulled out of the board I redid the test.
> 
> With the leg removed and 8 VAC applied, the motor did not operate at all. I checked the voltage at pin 1 and got 3.4 VDC, the next cycle got 2.6, the next was 3.4, again, the next was 2.6, again, etc. etc.
> 
> swede


As I suspected. I think something is keeping the REV output of the flip-flop held high. Downstream electronics appear to be okay. In any event it sounds like your CD4013 is bad. Replacements are inexpensive, I found them for 48 to 50 cents at Mouser. Shipping, as usual, will drive the overall cost higher.

As others have suggested try to find a socket, solder that to the board, and insert the chip. It will save headaches in the future should the chip malfunction again. It is a CMOS device so proper handling is paramount. You should be grounded (static wrist strap) at all times when handling static sensitive devices.


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## rrswede (Jan 6, 2012)

As this thread has progressed, the likelihood that the 4013 was the culprit grew and grew. I was hoping to unsolder and replace the two little transistors and be done. Individually unsoldering the 14 pins and getting the chip removed from the board seems like a daunting task. 

I found a video on the internet (link attached) that shows a chip being removed and am curious if his approach is practical in this instance.






Thanks, swede


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## wvgca (Jan 21, 2013)

well, kindof ..
easiest way is to cut each leg next to the body, and remove each leg seperately...
after all, you're not saving the ic


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## Norton (Nov 5, 2015)

wvgca said:


> well, kindof ..
> easiest way is to cut each leg next to the body, and remove each leg seperately...
> after all, you're not saving the ic


What he says. Unless you have a special soldering iron tip that heats all the pins at once (very old school) or a small heat gun tip its not worth trying to save the IC. Just cut the pins one by one and unsolder them one at a time.

Pete


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## gunrunnerjohn (Nov 10, 2010)

The above is also how I take them out. With either thru-hole or SMT parts, it's far easier to deal with individual leads than trying to take the whole part out intact. 

I don't attempt the really fine pitch parts with legs on all four sides anymore, but when I did them, I used a Dremel wheel to carefully cut the leads at the body and then just sweep them off with the iron.

Piece of cake.


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## rrswede (Jan 6, 2012)

Thanks for the comments, Warren, Pete and John.

I do have a small diameter Dremel cutting disk with a long shank that should allow me to gain access to the pins without damaging the board. My smallest pair of wire cutters are not the up to the task.

The video looked intriguing but dicey.

swede


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## highvoltage (Apr 6, 2014)

rrswede said:


> Thanks for the comments, Warren, Pete and John.
> 
> I do have a small diameter Dremel cutting disk with a long shank that should allow me to gain access to the pins without damaging the board. My smallest pair of wire cutters are not the up to the task.
> 
> ...


As GRJ mentioned, cut the leads off at the body of the chip. That way you'll have something to grab onto when you unsolder them.


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## Norton (Nov 5, 2015)

Swede, its worth investing in a good pair of 4" diagonal cutters. You will find then very handy for everyday work. I prefer the pointed flush cutting type for finer work.
Besides cutting wire they are excellent for removing parts from plastic sprues found in kits.
Pete


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## rrswede (Jan 6, 2012)

Highvoltage and Norton, thanks. 

I have several pairs of diagonal cutters. One pair, by Klein, is a flush cut 5" that is a very good "nipper". The spacing between pins is small and the extreme end of the tip barely fits. It would be my first choice when trying to sever the pins, however. The smallest, 4", is of typical design and more robust, but the jaw tip is too big to nip the tops of the pins. 

I plan to use the Dremel, positioning the cutting disk parallel to the sides of the chip and cutting the tips of the pins where they bend to enter the chip. I'll use forceps to secure and remove the pin when each is unsoldered. 

swede


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