SS DMD

[jonathan]

DMD was working fine. Moved the
Game, turned it back on. It was still fine for 2 minutes then just went off. I've reseated both cables to no avail? Any ideas? Is the DMD fused?

 

[pinballmania]

Power supply gone bad I expect. Usually the 62v. Measure the voltages carefully

 

[jonathan]

From where to where?

 

[cooldan]

Presumably on the connector that brings power to the DMD board. Should have about 118V, 106V, 5V, 12V, and 65V I think. Some of those may be minus voltages. Black on ground, red on the pin you're testing. On DC volts.

 

[jonathan]

Thanks, I'll have a look on Saturday

 

[jonathan]

Power supply gone bad I expect. Usually the 62v. Measure the voltages carefully

65v has gone

Next question, which part do I need to replace to fix it? The HV has already been rebuilt once by the looks of it

 

[pinballmania]

Check the 47k resistors first. You'll need to lift one leg of the two big capacitors off first to get any plausible reading.

 

[jonathan]

And what reading should I be getting through the resistors?

Do you mean unsolder one side of each capacitor?

 

[pinballmania]

47k

 

[pinballmania]

Yes. Otherwise your meter will just charge the capacitor and affect the resistance measurement.

 

[stoptap]

Andy's high voltage re-build kit is only £5.50. Just re-do the whole thing. Doesn't take too long and you know that you're not going to be fixing one thing only for another to fail soon after.

 

[RudeDogg1]

Andy's high voltage re-build kit is only £5.50. Just re-do the whole thing. Doesn't take too long and you know that you're not going to be fixing one thing only for another to fail soon after.

I concure

 

[jonathan]

We have life

 

[Spandangler]

Nice work. Was it just one of those little capacitor reissitory things?

Edit: just seen it was the hv kit

 

[stoptap]

It is one of the most satisfying repairs. Cheap kit, a bit of a faff but great reward when that DMD springs back into life.

 

[jonathan]

I found the schematic online so it was likely to be one of 2 X 47k resistors. Took 5 mins to change both

If it goes off again il swap the whole lot

 

[cooldan]

good man, always very satisfying to fix something, especially after firing up the soldering iron

 

[pinballmania]

Check the 47k resistors first. You'll need to lift one leg of the two big capacitors off first to get any plausible reading.

[emoji3]