Repairing traces on an ST keyboard

[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 (304.5 KiB) Viewed 3255 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 (340.76 KiB) Viewed 3255 times

This area has copper that has completely been eaten away

PXL_20210215_115925177.jpg (253.43 KiB) Viewed 3255 times

Sand it down, run flux and solder over and start laying wire

PXL_20210215_121512200.jpg (375.06 KiB) Viewed 3255 times

Wire laying finished

PXL_20210215_123259072.jpg (330.21 KiB) Viewed 3255 times

Spray with pcb lacquer

PXL_20210215_123704157.MP.jpg (276.07 KiB) Viewed 3255 times

[DoG]

Looks really nice. Much cleaner then a keyboard repair I did.

[Steve]

Cheers Yours was a bit more extreme of damage tho! hehe

[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!!

[exxos]

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!

[exxos]

@Steve be careful the wire doesn't interfere with the rubber cup as it sits down..

[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 (296.54 KiB) Viewed 3192 times

PXL_20210215_174528548.jpg (325.8 KiB) Viewed 3192 times

Push the broken part back in to place with a little force, strengthen with some glue.

PXL_20210215_174755966.jpg (349.89 KiB) Viewed 3192 times

Scrape away the lacquer, check continuity

PXL_20210215_180403516.jpg (354.21 KiB) Viewed 3192 times

Add flux and go over with solder. Add new wire and solder to trace

PXL_20210215_184531625.jpg (327.02 KiB) Viewed 3192 times

Finish by spraying with new pcb lacquer

PXL_20210215_190656630.jpg (297.99 KiB) Viewed 3192 times

Rear side has had glue absorbed into the cracks for strength

PXL_20210215_174840063.jpg (322.91 KiB) Viewed 3178 times

[rubber_jonnie]

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!

Yup, I have to agree