Rusted out ZMC2

everten

Edo Express Delivery Guy
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Sep 2, 2012
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348
Any advice on this one? Boots into game, some graphics just show as large solid blocks. The ZMC2 has a leg that's completely rusted. I don't think I can get wire on it, there's nothing left and the pads look pretty bad around that area.

Diagnostic rom all regular test pass. Z80 test shows error expected C3 actual 00.

49589705678_aa5e01d574.jpg
 

HeavyMachineGoob

My poontang misses Lenn Yang's wang
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About all you could do is get a micro file and sand away at the plastic housing of the chip to expose more of the remnants of the missing leg. Not like there's much to lose in potentially damaging the chip. Some of the other rusted pins look like their traces go under the chip, they may be ok. It does appear one of the pins is supposed to go a short distance away from the chip to a via throughhole, you can see one that isn't rusted near it.
 

DaisyAge

Galford's Armourer
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Jun 10, 2018
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For rust I usually start with white vinegar and a hard bristle toothbrush to get the bigger pieces of rust off and to make any other reactions inert. I second the micro file idea as there's not much else you can do in that case. If you have deoxit I'd recommend using that in conjunction with the vinegar and hope most of the rust comes off. Worst case grab a beater board and swap the ZMC2
 

everten

Edo Express Delivery Guy
10 Year Member
Joined
Sep 2, 2012
Posts
348
For rust I usually start with white vinegar and a hard bristle toothbrush to get the bigger pieces of rust off and to make any other reactions inert. I second the micro file idea as there's not much else you can do in that case. If you have deoxit I'd recommend using that in conjunction with the vinegar and hope most of the rust comes off. Worst case grab a beater board and swap the ZMC2


I don’t have deoxit, but that pic is after a toothbrush + white vinegar wash. I didn’t want to go too hard. I will probably try to grind away some of the chip to expose more of the leg.
 

shadowkn55

Genbu's Turtle Keeper
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I don’t have deoxit, but that pic is after a toothbrush + white vinegar wash. I didn’t want to go too hard. I will probably try to grind away some of the chip to expose more of the leg.

You may have to remove the chip entirely and see if there is any further corrosion under the chip. The pin that rusted off is related to the audio section, not graphics. This is why the z80 test was failing in addition to the graphics issue.
 

defalt

Cheng's Errand Boy
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Oct 12, 2017
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114
If this helps, I have a shit-ton of ZMC2s laying on a shelf. I can send you one, just pay shipping. PM if interested.
 

everten

Edo Express Delivery Guy
10 Year Member
Joined
Sep 2, 2012
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If this helps, I have a shit-ton of ZMC2s laying on a shelf. I can send you one, just pay shipping. PM if interested.

That would be awesome, PM incoming.

I managed to remove the chip, it looks pretty rough underneath. Some pads might be missing.

Where can I find a pin out / schematic so I can test the traces from the pads?
 

ack

Ninja Combat Warrior
15 Year Member
Joined
Apr 9, 2009
Posts
538
On the dev wiki, the image of the chip shows the inputs and outputs of the IC. The pins with the arrow/triangle that point in are inputs, the ones that point out are outputs. In the case of the ZMC2, the green input pins (C0-C31) are the incoming sprite data, the ZMC2 transforms that data and it pops out the green output pins (GAD/GBD0-3). All of these pins should be pulsing.
 

vicsidious

n00b
Joined
Jan 19, 2023
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1
If this helps, I have a shit-ton of ZMC2s laying on a shelf. I can send you one, just pay shipping. PM if interested.
Bonjour Defalt!
I am in the process or repairing my two-slot and I suspect the issue is with the Neo-ZMC2 chip, since I’m plagued with the dreaded vertical lines of woe…
While searching for a solution, I came across this post. If you still have access to these NEO-ZMC2, I would like to buy two of these chips from you.
Please let me know if they are still available, I would love to be able to play Metal Slug again, sans vertical lines!!

Please reach me at vicsidious(at)hotmail.com, it will be a pleasure to hear from you. I do speak french too so don’t hesitate if tou do too!

Cheers!!
David!
 

maki

Edo Express Delivery Guy
Joined
Jan 1, 2022
Posts
332
If you still have access to these NEO-ZMC2, I would like to buy two of these chips from you.
I don't have any, but Furrtek sells replacements on tindie:


I bought his NEO-BUF replacements and other things before, good stuff, cool guy.

Also, no need to cull original carts with these replacements.
 
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