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Not sure I'm measuring correctly. I put the red probe on pin 10 or 11 and the other to ground. I get 0Hz on either pin when doing that.

I've finished! A complete PDF as well as individual pages is available here: https://drive.google.com/drive/folders/10VO6n72vsn52xqMyOgSZpi11tbyv7_Yx I tried to keep the drawings as close as possible to their originals, but some modifications were unavoidable. There are some labels that might...

Also tested on the bottom of the board: R20: 1.2kΩ R21: 48Ω R22: 48.6Ω R24: 73Ω C40 couldn't be read with my ESR meter, but the same goes on a known good board.  Continuity is okay from the connector through the passives and UG6/UG7.

Also replaced UA8, UB8 and UC8, but the symptom didn't change.

Pin 6: -5.8V Pin 7: -13.38V Pin 9: 0.34V (Composite Video) Pin 10: 0.327 (HSYNC) Pin 11: 0.257 (VSYNC) Pin 12-13: 5.5V Pin 14: 13.8V Though the rails seem high, 5 other boards work okay attached to this analog board/PSU. EDIT: On a couple of working boards I get the following values...

Added another sheet and cleaned up more stuff on the others. All three should be in good shape now. What do these asterisks (or are they bullets?) on the sheet labels mean? Inversion?

I've just updated the link above to a version that should be properly shared.

I've updated the video interface and finished the CPU/FPU page. New link to a folder where I'll add the others: https://drive.google.com/drive/folders/10VO6n72vsn52xqMyOgSZpi11tbyv7_Yx They're still just PDFs, but when I figure out how to properly redact, I'll share the KiCAD files too...

Reflowing J12 did not change the symptom unfortunately.

I will try reflowing J12, but I was probing to it when testing power and ground on the ICs. I did try hitting reset and could hear a very slight blip (not chime) from the speaker, but no other activity. I checked the traces under C2 in case the reset line was broken, but I think it's okay. If...

This MLB doesn't chime or display any video. A working MLB in the same enclosure works okay. It was recapped and reworked by Uniserver last year but didn't work when I got it back. The following has been done so far: Swap tested with known good parts: ROM Processor (it's socketed on this...

I tested the following again with a multimeter and all seem okay. I don't have a scope so can't test live. A0: UD8 pin 4 to UK6 pin 10 A1: UD8 pin 12 to UK6 pin 9 A2: UC8 pin 4 to UK6 pin 8 to ROM pin 4 A3: UC8 pin 12 to UK6 pin 7 to ROM pin 5 A4: UB8 pin 4 to UK6 pin 6 to ROM pin...

Not the joints, spray the pins and interior of the receptacle.  oops didn't read the whole reply :)

I've had this happen to multiple Plus's. All it took to resolve was spraying down the connector at J1 with contact cleaner and they worked well long after.

This SE/30 MLB displays distorted horizontal and vertical video but does boot okay. The board has been recapped and most traces for video have been tested. It's also had UA8, UB8, UC8, UD8, UE8, UF8 and UG8 replaced. I swapped in known-working chips into UE6, UE7, UG6, UG7, and UI6. I sprayed...

@BolleThanks for the tip. I'll do a comparison and update the file accordingly.

Thanks! It took maybe 6-8 hours over several days. The others should be faster now that I've learned the tool. Yes, KiCAD can create a PCB design that's connected with the schematics. But I suspect recreating the board layout would take a substantial amount of time and effort. Anyone here want...

Weird. I just used the file attachment thing in the forum. Anyway, here's a link to it in google drive. https://drive.google.com/open?id=1Q835q_GF0Ysb0uEYos984YFyEAN2WxQy

Hm it's working okay for me. It's just posted as an attachment to the forum. Do you maybe have an ad blocker or some other filter for this site? You might need to turn that off.

I took a crack at doing this in KiCAD for the video interface schematic. I've never used the tool before, but was careful to make sure everything connected okay. I'd love some help double-checking it. I'm willing to post the schematic files themselves but need to figure out how to strip...