My Timeharvest CMVS seems fried for a second time

bobrocks95

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After some extensive via probing and trace routing...

Pin 26 (A13) on the NEO-DCR-T has trace damage and does not connect to CPU pin 44 as it should. This is in the damaged area with what someone said was nail polish from an earlier post. Don't see why one address line would make the whole thing stop working but I'm going to try a fix later tonight. The pins on the DCR-T are pretty fine pitched though so it's going to suck with my soldering skill level, but probably better than trying to solder to the via on the underside of the motherboard.
 

BIG BEAR

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multiple components link to that DCR-T which would be pin 230 of the CRZ, pin 36 of the bios and pin 2 of the both backup rams and work rams. Also B17 of CTRG2(cartridge slot 2)
BB
 
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bobrocks95

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multiple components link to that DCR-T which would be pin 230 of the CRZ, pin 36 of the bios and pin 2 of the both backup rams and work rams. Also B17 of CTRG2(cartridge slot 2)
BB

Maybe that will explain BIOS not booting properly and the pink garbage? We'll see!

It doesn't explain two MV-1C boards dying on me, but maybe it was a fluke and these are quite prone to failure... They're certainly getting expensive these days but I figured that was the vertical slot being more desirable for CMVS builds.
 

BIG BEAR

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The MV1B is prone to failure imo,the MV1C not so much... If you want to trade your bad boards in as credit towards a good board, drop me a conversation. No top covers needed in the exchange if you choose to do something like that.
BB
 

bobrocks95

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DCR-T bodge wire didn't do anything. I'll look for any other damaged traces but maybe the CPU is just fried. Extremely disappointing... People told me earlier a diagnostics BIOS wouldn't do me any good since the BIOS isn't even booting, yeah? Not even getting the click of death watchdog so don't know if the CPU is spinning at all.
 

bobrocks95

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It's fixed! After the trace patch my unibios must not have had 100% contact from a bit of excess solder on the CPU pin I soldered to. I took some wick to the top of it and gave the whole CPU just a touch of fine sandpapering and alcohol afterwards to make sure connection would be good.

OR it's because when I went to try stock BIOS again, I noticed pin 10 (the one you solder to pin 21) was barely hanging on and it broke the second I touched it, so there's a possibility it didn't have a good connection to begin with. This is just being tied high since pin 21 is +5V, so not sure if leaving it floating was a major issue or not- it normally connects to pin 7 on the DCR-T. I'll feel pretty stupid if that was the problem the whole time, but I think it still had a good connection after the initial install and the damaged trace was the real problem initially.

I was able to get some solder to stick to the nub of metal still sticking out thankfully... I've seen the dremel work some people have had to do for broken chip legs before so glad that wasn't needed.


Final question- I'm missing right stereo audio after hooking up the connector for the Timeharvest mod again. This is done on the underside of the board by soldering to some SMD resistors instead of most guides that show a top connection. Does anyone know how you're supposed to tap R103 and R96 like this for stereo? I think it was originally using the other side of R96...

1647583988967.png
 
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bobrocks95

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Oh and thanks everyone for the help, everything said was helpful and got me looking, it just took a lot of work! I'll keep an eye on this Timeharvest unit and hopefully I'll be much better at troubleshooting next time I have a problem. Maybe I'll swap out the power supply either way just to be safe.
 

bobrocks95

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Does anybody know why my built-in no cartridge connected sound test wouldn't work? Audio in games is fine now, jukebox in unibios menu also works, but I wanted to double-check that I still don't have left and right swapped.

This should be proper stereo wiring for that tap point on an MV-1C, those resistors connect straight to the top-side 8-pin chip that most mod guides show.

Miraculously all 3 wires are connected incorrectly for the Timeharvest unit from this picture of a review for it I found online. On my revision of the hardware at least, yellow is left, red is right, and black is ground.

1647647220511.jpeg

EDIT: If anyone sees this flip Left and Right audio connections, the Neo Geo digitally flips its audio channels so it doesn't match the DAC's datasheet pinout.
 
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bobrocks95

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That sound test doesn't work with the MV-1C. That's normal.

Interesting that they would break a built-in BIOS test on a revision and not bother to fix it.

Any games with a sound test or obvious panning to test my stereo configuration? Maybe KOF or Samurai Shodown pan when you're on the ends of the stages?

EDIT: Alpha Mission II was a great game to test and see that left and right are swapped and my diagram is wrong lol. The JNX tutorial has a correction in text but the photo is still using the incorrect labels, and that's what happens to come up when you google "MV1C stereo mod"...
 
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I also have one. Eh, actually two...
They really seem on/off for quality. Mine has perfect stereo out of the box (from two rear audio out). Actually the sound output really rocks.
Wasn't there a past issue with Scart cables/voltage? Watch out on the cable you use.
 
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