072 switch

[bigdogjeff]

Hi I have a o72 switch that doesn't want to work right any more. I took apart oiled & greased  and put back together and still didn't work opened it back up looked a little closer at it on test bench and the copper on the contacts are worn down in spots is there a way to fix this. I know there is 1 guy on here that knows a lot about these switches any help will be great . Thanks in advance

[bigdogjeff]

Here is a look at what going on

[Hap]

At first glance, it just looks like the contact strips are worn through on upper right and lower left.

[bigdogjeff]

Yes that's what wrong so that's what I need a fix for

[Curmudgeon]

Since those are printed circuit boards (PCB's), rather than the originals made before there were PCB's, you are going to have some difficulty if not skilled.

The easy fix, to keep from trying to get you to sweat solder a new copper or brass face onto those strips (if you've never done it before), is to cut some new brass contact strips, oh, .005" or maybe .010", with the tab on the side for the wire.

Unsolder the existing wire, file and sand the rough spots smooth on the old pads, and epoxt the new pads over the old.

There is enough play in the contact points to make up for any higher pads.

Hold the new pad in place until set in the correct location and orientation.

If you are good with soldering, you can sweat solder the new pad over the old, but don't overheat the board and damage it.

Dave

[bigdogjeff]

Will try this . I am very good at soldering just wasn't sure if that could be done 

[gunrunnerjohn]

I take the board out of a junk switch and put it in the switch to be repaired.  You'll need the proper rivets and tools, but it's a pretty easy fix.

[gopherstate]

I,ve had the same issues and repaired them by soldering on new brass strips.  It's not the easiest operation, but it can be done.  I've found it much easier to just replace the entire switch motor with one from a postwar 031 switch.  They are completely interchangable and the old ones are of much better quality.

Matt.