After replacing the same 3 transistors I had in the past (posted above) I test powered it up and it didn't sound good, lots of noise. Luckily nothing further blew (that I know of), no smell, no blown fuse.

There is a row of 4 small glass diodes. In the same area as the blown transistors.
Two of the diodes were blown (shorted). One of the two 5.1V Zeners and one of the generic "jelly bean" diodes (I'll get details on that if needed).

So it powers up all quiet now. I've been testing it at work where I have a very old beaten pair of 18 bit DSP5000's, with 7 segment displays. The backs I'm repairing are from DSP5000 Smiley (their cabinets are 125 miles north)

When I hooked them up the 7-segment displays just constantly flash every LED. I was not sure if there were more problems or just not compatible and need to test with a Smiley Display.
I then tried my 2nd Smiley back in the same 18 bit/7-segment cabinet which I know is working and it did the same thing.

One other difference is these old 18bit are 220V UK Speakers with a step up transformer I use externally.

I have mixed and matched 18bit, 24 bit 7-Segment and Smiley in every combination you can imagine, as well as 240V vs 120V Power Supplies and never had any trouble.

Am I just forgetting something? Is the cable different or something. I think the repair is good, but I'd like to confirm before bringing them back north. And I prefer not rip apart yet another smiley to verify.
I vaguely recall this blinking issue, like if it's plugged in backwards or off by 1 pin. But I triple checked. Red stripe to red stripe.

Any ideas?

One thought is when I tested earlier with the blown diodes maybe I damaged the power supply.

- Fiddler (IMHO)

If you think listening to music is fun, try learning an instrument.
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