AEKII Board Repair

[adfrost81]

So I picked up a used and non-functioning AEKII for $20 at Free Geek in the Twin Cities, thinking it could be fun little repair project. Worst case, I ruin it, and it becomes a parts board, retrobright practice piece or maybe I get a replacement PCB.

The main symptom is that all three lights are lit, and doesn’t respond when typing on any key. I noticed some corrosion on a few components, so I figured I’d try replacing those first. I got all the switches desoldered, but in the process many of the through-hole traces got damaged. Most of these were on keys where the leads were bent instead of straight. This is my first time doing this sort of thing…how repairable is this for a noob?

Also, the trace was damaged around the screws on either side. Seems like that probably need to be repaired somehow as well.

Any feedback would be appreciated!

 

[KennyPowers]

Where you've damaged a through-hole solder pad, use a hobby knife or scalpel to gently scrape away the solder mask covering the trace connected to the damaged area to expose some copper. Then, when you're soldering the switch back in, bridge the solder to that exposed copper. It will be easier if you use flux and tin the exposed copper first. Afterwards, verify all such connections with a multimeter or continuity tester.

 

[adfrost81]

Where you've damaged a through-hole solder pad, use a hobby knife or scalpel to gently scrape away the solder mask covering the trace connected to the damaged area to expose some copper. Then, when you're soldering the switch back in, bridge the solder to that exposed copper. It will be easier if you use flux and tin the exposed copper first. Afterwards, verify all such connections with a multimeter or continuity tester.

Thanks! That sounds pretty doable. I wasn't sure if solder would be enough or if I would need to "make" new pads somehow (probably with wire).

Another question: would I need to resolder ALL of the switches in order to test the board? Or can I just replace what appears to be the bad components and see if it will power on without the switches? I'd hate to desolder everything and find out it still doesn't work and have to desolder again.

 

[KennyPowers]

Another question: would I need to resolder ALL of the switches in order to test the board? Or can I just replace what appears to be the bad components and see if it will power on without the switches? I'd hate to desolder everything and find out it still doesn't work and have to desolder again.

I don't know much about keyboards, but I believe all of the key switches are single-pole, single-throw, so not resoldering a switch should be the same as not pressing that key. So no, I wouldn't think you'd need to resolder them all (someone correct me if I'm wrong or if any of the key switches are "special"). You probably do need to resolder/replace any chips or passive components you've removed.

 

[ShadeDream]

Another question: would I need to resolder ALL of the switches in order to test the board? Or can I just replace what appears to be the bad components and see if it will power on without the switches? I'd hate to desolder everything and find out it still doesn't work and have to desolder again.

If you have a pair of metal pointed tweezers, you can insert the tips into the vias for the switch and pinch gently to short it to test. This is standard procedure for testing PCBs in the custom keyboard hobby. If your switches are in bad shape, but you can get the PCB working correctly, you can buy some Matias Quiet Click switches which are essentially modern clones of the alps silent cream/whites typically used in the AEKII.

 

[adfrost81]

I don't know much about keyboards, but I believe all of the key switches are single-pole, single-throw, so not resoldering a switch should be the same as not pressing that key. So no, I wouldn't think you'd need to resolder them all (someone correct me if I'm wrong or if any of the key switches are "special"). You probably do need to resolder/replace any chips or passive components you've removed.

Yeah, explained that way, it makes logical sense. I'd definitely have the new components soldered in first (some capacitors and I think some diodes).

If you have a pair of metal pointed tweezers, you can insert the tips into the vias for the switch and pinch gently to short it to test. This is standard procedure for testing PCBs in the custom keyboard hobby. If your switches are in bad shape, but you can get the PCB working correctly, you can buy some Matias Quiet Click switches which are essentially modern clones of the alps silent cream/whites typically used in the AEKII.

All the switches should be good...I'm more concerned about the board! I used to have a couple keebs with Matias switches (Matias Quiet Pro and KB Paradise V80).