Page 1 of 1

Repairing traces on an ST keyboard

Posted: 15 Feb 2021 13:34
by Steve
If you open up your keyboard and see dark spots on your keyboard traces, chances are moisture has gotten through the green keyboard lacquer and your traces have started to rot. Just repaired some traces today on a keyboard and took some photos:

Example of dark spots on traces

PXL_20210215_115941170.jpg
PXL_20210215_115941170.jpg (304.5 KiB) Viewed 3283 times
Example of traces that can be 'touched up' with solder to stop further corrosion. Rub down, add flux and run solder over. Then re-seal.
PXL_20210215_125512375.jpg
PXL_20210215_125512375.jpg (340.76 KiB) Viewed 3283 times
This area has copper that has completely been eaten away
PXL_20210215_115925177.jpg
PXL_20210215_115925177.jpg (253.43 KiB) Viewed 3283 times
Sand it down, run flux and solder over and start laying wire
PXL_20210215_121512200.jpg
PXL_20210215_121512200.jpg (375.06 KiB) Viewed 3283 times
Wire laying finished
PXL_20210215_123259072.jpg
PXL_20210215_123259072.jpg (330.21 KiB) Viewed 3283 times
Spray with pcb lacquer
PXL_20210215_123704157.MP.jpg
PXL_20210215_123704157.MP.jpg (276.07 KiB) Viewed 3283 times

Re: Repairing traces on an ST keyboard

Posted: 15 Feb 2021 14:25
by DoG
Looks really nice. Much cleaner then a keyboard repair I did.

Re: Repairing traces on an ST keyboard

Posted: 15 Feb 2021 15:04
by Steve
Cheers :) Yours was a bit more extreme of damage tho! hehe

Re: Repairing traces on an ST keyboard

Posted: 15 Feb 2021 15:32
by rubber_jonnie
For light corrosion I find that a fibreglass pen is excellent for cleaning up with minimal damage and you can either just re-lacquer or solder as you've done, depending on the amount of corrosion.

Just don't touch the end of the pen or you get nasty bloody fibres in your finger!!

Re: Repairing traces on an ST keyboard

Posted: 15 Feb 2021 15:51
by exxos
rubber_jonnie wrote: 15 Feb 2021 15:32 Just don't touch the end of the pen or you get nasty bloody fibres in your finger!!
Needs at least 100 more exclamation marks! :lol:

Re: Repairing traces on an ST keyboard

Posted: 15 Feb 2021 15:52
by exxos
@Steve be careful the wire doesn't interfere with the rubber cup as it sits down..

Re: Repairing traces on an ST keyboard

Posted: 15 Feb 2021 19:09
by Steve
@DoG just did a repair in the same place as yours lol, must be a popular place to punch an ST :)

PXL_20210215_173330748.jpg
PXL_20210215_173330748.jpg (296.54 KiB) Viewed 3220 times
PXL_20210215_174528548.jpg
PXL_20210215_174528548.jpg (325.8 KiB) Viewed 3220 times
Push the broken part back in to place with a little force, strengthen with some glue.
PXL_20210215_174755966.jpg
PXL_20210215_174755966.jpg (349.89 KiB) Viewed 3220 times
Scrape away the lacquer, check continuity
PXL_20210215_180403516.jpg
PXL_20210215_180403516.jpg (354.21 KiB) Viewed 3220 times
Add flux and go over with solder. Add new wire and solder to trace
PXL_20210215_184531625.jpg
PXL_20210215_184531625.jpg (327.02 KiB) Viewed 3220 times
Finish by spraying with new pcb lacquer
PXL_20210215_190656630.jpg
PXL_20210215_190656630.jpg (297.99 KiB) Viewed 3220 times
Rear side has had glue absorbed into the cracks for strength
PXL_20210215_174840063.jpg
PXL_20210215_174840063.jpg (322.91 KiB) Viewed 3206 times

Re: Repairing traces on an ST keyboard

Posted: 15 Feb 2021 21:43
by rubber_jonnie
exxos wrote: 15 Feb 2021 15:51
rubber_jonnie wrote: 15 Feb 2021 15:32 Just don't touch the end of the pen or you get nasty bloody fibres in your finger!!
Needs at least 100 more exclamation marks! :lol:
Yup, I have to agree :lol: