Zed Blade - Bad Repair or Partial Boot?

DNSDies said:

I've gone ahead and circled some points to test for continuity. "D" I'm assuming goes to a cart-edge pin.

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Why are you marking dead/unpopulated pins?

Because I'm not terribly familiar with Neo Geo cart circuit layouts, and I don't know if those traces continue on to other ROMs elsewhere on the opposite side of the board, and I was just marking good places to test for continuity on either side of the corroded traces.

a, c, d, e, f, i, and h may lead nowhere, in which case one can ignore them.

But b, g and h are all going to populated pins.

DNSDies said:

Because I'm not terribly familiar with Neo Geo cart circuit layouts, and I don't know if those traces continue on to other ROMs elsewhere on the opposite side of the board, and I was just marking good places to test for continuity on either side of the corroded traces.

a, c, d, e, f, i, and h may lead nowhere, in which case one can ignore them.

But b, g and h are all going to populated pins.

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The logic flows left for those pins so the pins to the right won't affect them.

ShootTheCore said:

View attachment 23855

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On a side note, blue seems to be a little too high? What are you playing this on?

Xian Xi said:

On a side note, blue seems to be a little too high? What are you playing this on?

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This is from an Omega CMVS connected directly into a Samsung HL67A750 via component cables. My iPhone camera and the fluorescent lighting is probably throwing the color off in the picture - IRL the TV output is outstanding.

Make sure when you connect the two points that you have to scrape off some of the blue stuff to solder to it.

No luck unfortunately. First, I cleaned both boards up extensively with Deoxit and Q-Tips. Then I carefully scraped the blue stuff off of the contact point connected to the rusted terminal and checked the continuity. It passed, but the music track was still bad on my MVS. So I carefully scraped the blue stuff off all of the contact points around the V-ROM banks and checked the connections between all of the V-ROM pins to the contact points. In the end, the symptoms are the same - CRC check still passes, but the last level music is still corrupt.

I'm guessing that Xian Xi was correct with it being a PCM problem. I think it's time for me to hand the cartridge off to someone who knows what they're doing. Who would be willing to diagnose and repair this for me? I'm willing to pay for the repair service.