Broken wires between flat and ctrl amp sx-1250

[rsmcatskills]

During the refurb 3 of the interconnect wires between these two board broke from fatigue right at the base of the wire wrap. Not enough wire to re-wrap. What is the preferred fix - I'm figuring the answer will depend on the intent of restoration . Whether I am looking for originality or if I just want to make it work. Well, I'm some place in the middle but I don't want to work on this thing the rest of my either. The gauge looks to be 22 awg and I don't see that available in wire wrap type wire, Maybe I don't know what to look for. Re-wrapping would be my preference but don't want to spend 100.00 in wire ( need 3 colors). Any thoughts.

 

[mattsd]

Photos would help identify the wires in question. I have a 1250 currently open, so I can help get them put back in place.

 

[markthefixer]

Re-wrapping needs a special tool, that is expensive as well. It''s not just wound around the post, it is done under tension, so that there are literally TONS of force on the sharp corners of the pin biting into the wire, to form "gas tight" connections. the reliability comes from 4 cuts per turn and ten turns.

If it's just plain wire, solder in wires to the pads. The pins are old and oxidized and it takes significant effort and skill to get them to take solder. Brush on flux helps. Better to just heat up the solder holding in the pins and remove the pins. Wire wrapping was a valid assembly method for a factory, but recreating it is a pita.

 

[Craftsman11]

MTF-- I want to thank you for your generous contributions to this forum. I'm new to this and appreciate your help.

Maybe a dumb question but RE: wire wrapping-- has anyone tried soldering connectors on to the wire ends so that they can be easily plugged/unplugged on the board pins? If so, what type of connectors were used? If not, what is the best solution to connect the previously wound wires back on to the pins?

 

[rcs16]

Easiest and cheapest method is to solder the wires to the old sq posts. You can put a bit of heatshink over the end of the insulation so it does not wick/melt back as much. The sq pins and wire could use a bit of sanding/filing to remove old oxide for the solder to flow properly to the pin.
After the wire has been unwrapped it is very brittle from the wrapping action, so you might have to extend the wire lengths if you run short. Use ferrules and heat shrink in this case.
There are connector and terminal block options as well, but the pin spacing is not always uniform.