# DCC track voltage



## santafeguy (Oct 11, 2012)

Ah, ha! Maybe I just found a big problem: My MRC wireless Prodigy manual implies a track voltage of 14.5. Using my digital volt meter on AC scale, I just measured 16.5 volts on the track with no locos present. Would that be enough to cook all of these sound decoders I'm toasting??


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## Mrs.NIMT (Aug 17, 2012)

I wouldn't think so... but NIMT will be along shortly with a much better response!


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## Brakeman Jake (Mar 8, 2009)

No,it's not your problem.First,most decoders if not all can take this voltage without any problem.Also,your reading is a "no load" voltage wich often will be a little higher,try to read it again with some load on the track.


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## NIMT (Jan 6, 2011)

Brakeman Jake is right, Voltage is not your problem.
I can run all my decoder installs up to 18 volts.
What problems are you having with the decoders or the installs?


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## santafeguy (Oct 11, 2012)

*MRC voltage*

Thanks, guys. Here's more info. The system is an MRC Prodigy Advanced wireless. It's a small layout, essentially a "one engine railroad" (13' X 13" walkaround.) First to go was a Quantum Revolution. Ran great for a while, then one day after I turned on the layout, it acted strange. Next time it was dead. Replacement was a new Titan. Absolutely loved it! Then...same thing. Ran great yesterday, dead upon turnon today. Replaced with another Titan, same thing. Thinking maybe it's the loco (Athearn 2-8-2), I just replaced it last night with a new BLI Heavy 2-8-2 w/Paragon II sound. Ran great for about 10 minutes, now it's dead. No shorts on the layout. Engine didn't derail.
At one time, I thought it might be a start-up power surge in the system, so I now have surge protectors all over the place, including directly before the DCC system. AND...a silent GP-7 w/ an NCE decoder continues to run fine.

I'm stumped!!!!


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## Brakeman Jake (Mar 8, 2009)

Though not totally impossible,it's hard to believe that four decoders would be bad.When you say "dead",do you mean nothing at all?Or sound without propulsion?Does sound come up when powering the track?Have you tried reading these decoder's CVs?Tried resetting them?When you removed them,did you notice any burn mark or a strange smell?If no physical dammage is noticable,may be that somehow these decoders have CVs scrambled.

You have a GP7 going fine,for what it means,it is a silent one and a diesel,but still it indicates your DCC system should be OK.A strange problem indeed.Tell us as much as you can,may be Sean will think of something.


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## santafeguy (Oct 11, 2012)

*fried decoders*

I REALLY appreciate your help! More info:
In each case, the decoder worked great for while. Typically, they would be fine when I turned off, dead when I turned on tomorrow. "Dead" meaning, no sound, no propulsion, maybe the headlight lit, but no communication. Neither cv reset nor physical reset did anything. Previously, occassional issues with weird behavior such as suddenly stopping as though it had lost connection with the track. Then I'd wiggle it and it would come back on, but the track is clean. Sometimes back to normal, sometimes it had reverted to default. (This was the Athearn 2-8-2 that has no tender pickup, only the drivers.) This could happen on a simple section of straight track, not just on a turnout or something. Weird stuff! Once, following an event of weirdness, the decoder seemed "dead". I gave up, shut off, and left in frustration. I came back the next time, powered up and...voila!..the engine suddenly came back to life! But a week later it died for good. The new engine that lasted 10-20 minutes stopped as if no power. I got it reset it and it was running fine. I was switching cars with the engine on a switching lead, not on any turnouts, when it just quit. Sudden silence, no motor, no communication, nothing. But headlight is lit. Neither cv reset nor physical reset brought it back.
This is too strange for words. The decoders have not shown any obvious "cooking", but they do seem to run hot. I'm electrically savvy, but no dcc genius. It seems like it must be either the MRC system or something about the layout.


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## Brakeman Jake (Mar 8, 2009)

Well...I'm running out of ideas but still,I,ll give it another try.Let's try a step by step questioning...
First,what's your programming set-up?Do you have a prog. track booster?I have serious doubts that your MRC system can program sound decoders properly.I couldn't program my Tsunamis without it.I also had a similar problem with a pair of MRC decoders...I could program the adress but when trying to read CV's,they gave me weird numbers.So you may be trying to reset without knowing if it actually does and no way to verify.

Then,if you can program and read,I suggest you try resetting again and read them before operating them.If numbers come out OK,then try running the engine.

I assume you don't have another DCC system...could you borrow one from a friend or may be a local hobby shop?Or just as good,bring your loco there (friend or LHS) to test it.

If not possible,do you have a DC control...they won't have all the bells and whistles but sound decoders usually run on DC(if programmed to do so).If they do,that would suggest the decoders aren't the problem.Even if their adress is messed up,DC should have them moving.

I've had a problem that was pretty similar to yours a while ago.I had thoroughly tested a brand new Kato (SD40-2) on DC,had it creeping at very slow speed for a while and all was fine.I then installed a Tsunami in it,it ran great for a few minutes than started glitching then went dead.Touched it,it came back alive to start glitching again.Cleaned the track thorouhly to no avail.Install another Tsunami...same results.I suspected my DCC set so I sent the decoder to Sean for testing...decoder is fine.I've since dropped the idea of a sound decoder in this loco,installed a TCS M1 silent decoder and the "thing" runs just great at all speeds,creeps fabulously slow a throttle step 1.I still don't know what's wrong with it...some gremlin that neither DC or a regular decoder see but a sound decoder picks up in no time.

Whatever comes out of your testing,don't throw your suspicious decoders away...send them to Sean (NIMT),he's got the right equipment and he'll find the problem.Better still,send the whole loco.But,like you,I do suspect your DCC system might be scrambling decoders.How?I don't have a clue.....


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## santafeguy (Oct 11, 2012)

Awesome. I am SO thankful for your help. Just time for a quick note tonight, but one very interesting item. I was getting the new, dead, engine ready to return to the dealer. He suggested a note to BLI to see if they had anything to suggest. They suggested trying the physical reset again and gave the complete procedure. Turns out I hadn't done it right. Tried the right way a minute ago and...IT WORKED! Well, that's better than a dead $200 engine...but at this point I don't trust the system/layout. Thanks for your very useful suggestions and I'll get going on them. Gotta go for now...

Thanks, again!!!


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