# O-27 switch repair (1122)



## servoguy (Jul 10, 2010)

I just went through a bunch of 1122s and manual equivalents. All of them had bad electrical connections. Some looked like they had been wet, and some were pristine. It didn't matter. They all had loose electrical connections. I recommend you solder all the connections before you reassemble the switches. Work quickly because the plastic does melt a little. The rivet in the center of the fat center rail needs to be soldered at both ends. I used a 4-40 screw for the frog with a pan head screw which fits nicely into the depression in the bottom cover plate. When you drill and tap the hole, use a little WD-40 for cutting oil, and it will drill and tap much easier. I also replaced the ground terminal because I am not adding Bob's cap discharge modification. To do this, I polished the metal tab that sticks out of the motor housing and also polished the area of the stud that would be soldered. Then I soldered the stud to the metal tab. Then here is the tricky part. I put a thumb nut onto the stud and used a pair of channel locks to hold the stud tightly into the bottom cover plate. The channel lock jaws are slightly offset so I could have one jaw on the thumb nut and the other on the bottom cover without covering up the hole where I was going to solder. Then holding the channel locks in one hand and the soldering gun in the other and having the solder draped over the edge of the table, I was able to do this 3 handed operation by myself. You can check your work by making sure the cover is held tightly by the soldered terminal. I also soldered two of the tabs that hold the outside rails in place to make a good connection between the outside rails. I had one switch that had the ground terminal broken off and it was lost. I soldered a 4-36 pan head screw to the bottom cover and made a new terminal. The thumb nut holds it tight to the metal tab coming out of the switch motor. Bruce Baker


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