Kjetil's Information Center: A Blog About My Projects

Commodore PC 30-III Repair

The Commodore PC 30-III is a AT-class 286 clone PC running at 12MHz with 1MB of RAM. My first and initial problem was the battery failure upon booting:

Commodore PC 30-III Battery Failure

For some reason, It was not possible to get past this error and continue booting anyway, so a replacement was needed. I got hold of a Glitch Works GW-12887-1 which can replace the original Dallas 1287 RTC in this machine:

Commodore PC 30-III Dallas DS1287 RTC

This is unfortunately soldered directly to the motherboard. But I cut a socket and soldered that one on instead:

Commodore PC 30-III U201 Socket Replacement

In which the replacement fits nicely:

Commodore PC 30-III GW-12887-1

This got the machine booting properly. But after a while of playing around with Compact Flash disk replacements, magic smoke suddenly appeared. Which became my second problem. I located the source; a burned ceramic capacitor:

Commodore PC 30-III Burned Ceramic Capacitor

From what I could find out online, these capacitors can fail if cracks appear in them, and moisture gets in over time. So that's most likely what happened to this 30 year old component. I got a replacement and removed the bad one, which disintegrated almost by itself:

Commodore PC 30-III Capacitor Replacement

The brand new ceramic capacitor in place:

Commodore PC 30-III New Capacitor

The machine is now up and running again:

Commodore PC 30-III Front

Topic: Repair, by Kjetil @ 08/12-2019, Article Link