Tuesday, October 16, 2007

dmd driver board repair

Spent over 2 hours yesterday evening working on a dmd driver board.
DMD didn't work, one of the voltages (don't remember which one) was too low.

Ordered a dmd high voltage rebuilt kit from greatplainselectronics.com, it arrived fast. Nice product for a great price (buying the parts separate at my local electronics shop would probably cost me double).

But the soldering itself.. I really hate soldering these dmd driver boards.
Parts are pretty close to each other. I did start at the top (first did the 4 resistors, then removed the large ceramic resistors, the heat sinks, and moved my way towards the bottom of the board removing parts..
resoldering everything went the other way, first bottom of board and working my way up.

Each time I had soldered in a component I checked with my dmm resistance towards the next component, to make sure they were soldered correctly and I had no cold solder joints.

And still, when I finally tested the board in a pinball machine, the score display did not come on ?!
Aaaargh ! I've been busy for almost 2,5 hour and it doesn't work :(

It was already too late to do any troubleshooting, tonight I'll continue and measure the voltages.. (and test the board in another machine).
I hope it's not a big fault and I can repair this board, because else I would'be been cheaper off buying one of those high-voltage piggy-back boards you just put on top of the original dmd driver board.

Update: seems my soldering isn't as bad as I thought - check tomorrows post.