The lovely Sophia is getting a fresh set of capacitors on the A-Bus board today.

Unfortunately, replacing them did not noticeably improve the fault. That is still useful information.

The A-Bus board has now moved considerably further down the suspect list, so the next step is the mainboard. There are a lot more capacitors on that board too.

Delightful.

This eventually turned out to be the right direction. Replacing most of the mainboard capacitors produced a dramatic improvement, and the remaining capacitor work was completed later in April.

So the A-Bus recap was not the magic fix, but it helped narrow the investigation.