Wow, thanks for the great suggestions from everyone!? I implemented what I could with what I have on hand...
Coincidentally, I am also trying to get an Akai S1000 working again, and ordered a 35w 5v power supply (Meanwell LRS-35-5). The PS came today, so I rigged it into the circuit by pulling the pins from #s 3 and 8 on the Molex and tack-soldering leads. Same issue... the +5vdc is pulled down to 4.4, and blocks appear on the display. I figured this indicated a motherboard issue, but tried the other suggestion anyway and connected a 12ohm power resistor from the disconnected internal +5v supply to ground. This also pulled the voltage down to 4.4!
I suppose I could go into shotgun mode and replace all electrolytic caps (there aren't many). Traces on PS appear OK, I did not look under motherboard.
To Bill: My DMM (EEVblog/Brymen BM235) is true RMS, but does not have a separate RMS chip. I think that's fine for lower frequency measurement. Let me know if you think otherwise. (I'm not an engineer, I only play one on TV... ;-)
So... I toss this info out with great appreciation for y'all's responses!
BTW Nicole, I also have a Matrix 6R which is starting to act a bit wonky. Was planning (after this project and the S1000) to check PS, seat chips, clean ribbon cable connectors and such.
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peace,
Frank Dickinson
90 East Productions
