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IIgs keyboard not working at all!
Posted by: tommijazz91 on 2020-04-19 05:20:30
Hi everyone!

After some time searching for one, I Irecently bought an Apple IIgs keyboard for my SE/30 (the seller lives just 2 km from here, what a coincidence!). It is quite yellowed but the keys are quite nice and not sticky.

I plugged it to a SE/30 with a cord taken from a working AEK II but nothing happens. It appears to be totally dead. Either port doesn't seem to work.

Am I missing something?

Even the PCB doesn't appear to be too terrible.

I really wouldn't want to resell it or buy another one - they are too hard to find and import to Italy.

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Posted by: Lee Adamson on 2020-04-19 07:30:21
(Disclaimer: I'm just a hobbyist and I don't really know what I am doing half the time.)

If you have the appropriate test equipment, I'd start by checking to be sure that there isn't a short to ground on the power rails.  Certain types of capacitors can form a short circuit when they fail (old tantalums in particular).  I can't tell what those blue ones on your board are (metalized film?), but if you find a short on the power rails, then I'd start with them.  That being said, I've found that the IIs of the era seem to have used far better capacitors than the same-era Macs.  I've never had to recap a II, but old Macs are another story........

Failing that, I'd see if I could find a pinout for that controller IC and start poking around with an oscilloscope.  If that's what's bad, I think there's probably a pretty good chance that you could desolder a replacement from an appropriate Mac board of the same era to replace it (edit: assuming there isn't some special magic going on with that particular chip to make it an italian layout keyboard).
Posted by: tommijazz91 on 2020-04-19 07:39:59
Thanks for the reply! Unfortunately I don't have much equipment, I only have a voltmeter (if I can find where I put it) and I really don't know anything about electronics.

Is it difficult to find a short?

I really hoped the keyboard was in working order, but sometimes things don't go as expected...
Posted by: bibilit on 2020-04-19 08:36:50
Hard to say from your picture, but one solder joint looks dull (top right) on the adb connector. 

Also, two other ones seem to be broken. 
Posted by: tommijazz91 on 2020-04-19 09:14:30
Hard to say from your picture, but one solder joint looks dull (top right) on the adb connector. 

Also, two other ones seem to be broken. 
It seems like the best option is take it to someone who can repair traces and solder joints...

Thanks a lot!
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