ABI Boardmaster 4000 repair

Another new toy to play with, this is a very useful bit of test equipment that can test chips not only out of circuit but also when they are still in circuit. I bought this knowing it had some issues but they are very rare and sought after so you cannot be too picky.

First I wanted to fix the lcd backlight which would flash on for a second then go off, this is a common problem with these things. It also made it hard to read the self test fail messages so looking on UKVAC forum there is a thread explaining how to wire a generic laptop inverter in place of the old one. I was impatient though and did not want to wait 2 weeks or more for one to arrive from China. The two surface mount capacitors looked like they had leaked which I've seen many times repairing Sega Game Gears.

I replaced them with high quality radials and the screen was now nice and clear and made it easy to read the 14! fail messages. I won't go over all the error messages again here but if you want to read more check this thread on UKVAC.

Twelve of the error messages gave part numbers to six different relays which from reading in circuit with a multi meter I could see were bad. The other two error messages didn't point to any parts but I was able to find them by metering every relay, it turned out to be two on the out of circuit testing pcb.

After replacing the eight bad relays...

the repair is complete.

Suitable replacement relays can be found here. - Thanks trm.