don't mix meth & capacitors 🌋 [1990 Dr. Mario on 1984 Uniplay]

arcadetime

New member
Joined
May 1, 2024
Messages
27
Reaction score
13
Location
Vancouver, bc, Canada
A tradie from out Abbotsford's way delivered this hot mess to me in a frantic state. It's his father-in-law's and there's some emotional connection to the thing.
:)
1 - dr mario versus unisystem nintendo.png

Nintendo being Nintendo, they figured 3v is 3v so let's put a 2x AA battery holder on there, save build costs plus earn service loot later when the battery bursts out of warranty leaking alkaline all over everything in the area.
Which it did.

Tradie's neighbor offered to remove and replaced the AA enclosure. Guy really seemed legit, so tradie let him to the job. It worked! This guy really knows his stuff!

Enter the next technical issue, bad sound. Tradie's neighbor ID'd this as the "sound board" :)


3 - mystery board dr mario unisystem.png

Tradie dosen't know exactly which caps his neighbor replaced but in examining the back, it appears he recapped all the caps.

IMG_20250118_155254487.jpg




Tradie figures his (now in rehab) neighbor did the recap on meth and messed something up, sending an unexpected flavor of voltage back to the mothership, frying a linear amplifier and a 1 million ohm resistor (maybe more?)

IMG_20250118_155207825.jpg

So he brought it to me because I'm the "expert" (it says so on my google places listing) yet I've never replaced a capacitor in my life. My mother, brother, and neighbor across the courtyard ALL replaced capacitors of various sizes in their monitor displays, with a 0% success rate on their combined attempts so far. I'm just wise enough to stay away.

I accumulated a nice little pile of components, bought with sofa seat change from Lee's:
  • 1mil ohm resistors
  • 2x LM3900N quadruple op amp (that's the chip @ ground zero)
  • transistor pair KSA940 & KSC2073 (on the lady @ Lee's hunch. These are the green jobbies mounted to the heat sinks on the yellow mystery board)
on its way:
  • unisystem to jamma converter. (ouch not cheap)
documentation:
one last thing. Turn the board over and we've got little hairs. The lady at Lee's thinks these might be important. Are they jumpers? They're not jumping anything right now, just indiscriminately shorting.



5 - mystery hairs pcb board back dr mario unisystem.jpg

Clear enough, arcade pilots? What would you crusty veterans do in my position with this thing, and what would you tell this customer in distress? Toss me the FIRST thing that comes to mind.
 
Last edited:
Toss me the FIRST thing that comes to mind.

breaking-bad-pizza.gif


Don't mind me, I'm just here because the thread title mentioned meth. Good luck figuring out your technical question that I can't help with, though!
 
The solder job on the sound board and PCB do not seem to match. It is possible that the PCB was an earlier repair not done by a meth head.
 
Hi again pilots

After replacing the two singed bits, the PCB booted up to a yellow screen of death. Another boot changed the color to magenta, but no less a screen of death.

He agreed that we could put our multicade PC in there, but he's got a CRT so we'll need an adapter. I'd planned to buy this overengineered red one, BUT...

big pcb.png

As if the Chinese emperor himself bugged my chop shop, a new adapter board MUCH simpler and MUCH cheaper hit the market.

small pcb.png
Question: will the little guy work? I ONLY need to convert VGA to whatever's in his Dr Mario frame (CGA, right?)
 
The first one is a converter and will actually convert the video signal from VGA to CGA.
The second one is an adapter and is only changing the connector type, it will not change the signal.
 
The first one is a converter and will actually convert the video signal from VGA to CGA.
The second one is an adapter and is only changing the connector type, it will not change the signal.
wouldnt one always need to change the video signal? what's the use case for the smaller board
 
wouldnt one always need to change the video signal? what's the use case for the smaller board
The smaller board could be used for a PC that has a video card that can actually output a CGA signal, but only has a VGA port.
Or, if you have a monitor that can take a CGA signal but only has a VGA connector, then you could also use the smaller board to connect the two.
 
Hi again pilots

After replacing the two singed bits, the PCB booted up to a yellow screen of death. Another boot changed the color to magenta, but no less a screen of death.

He agreed that we could put our multicade PC in there, but he's got a CRT so we'll need an adapter. I'd planned to buy this overengineered red one, BUT...

View attachment 800637

As if the Chinese emperor himself bugged my chop shop, a new adapter board MUCH simpler and MUCH cheaper hit the market.

View attachment 800640
Question: will the little guy work? I ONLY need to convert VGA to whatever's in his Dr Mario frame (CGA, right?)
You would definitely want the GBS 8100 to do the conversion job. If your multicade PC has an ATI/AMD GPU you can instead utilize CRT Emudriver to obtain native 15khz/CGA video output and then you would want that second board to connect your PC to your current monitor. This alternative would also be much lower latency if it's a necessity.
 
Hi again pilots

After replacing the two singed bits, the PCB booted up to a yellow screen of death. Another boot changed the color to magenta, but no less a screen of death.

He agreed that we could put our multicade PC in there, but he's got a CRT so we'll need an adapter. I'd planned to buy this overengineered red one, BUT...

View attachment 800637

As if the Chinese emperor himself bugged my chop shop, a new adapter board MUCH simpler and MUCH cheaper hit the market.

View attachment 800640
Question: will the little guy work? I ONLY need to convert VGA to whatever's in his Dr Mario frame (CGA, right?)
@arcadetime if you decide to use a multi-case setup, I would be interested in the VS PCB & Dr Mario daughter card.
 
if the game isn't running and it's a single color screen it means the daughterboard needs to be reseated. taking it out is kind of a delicate process, you never want to pull anything out one sided. you have to progressively work either side until it comes free. then plug it back in. the outer single wipe sockets on Nintendo boards are a tricky art. a module like Dr. Mario runs on will not work with machine pin or dual wipe sockets, the pins are too large, so you have to just live with Nintendo sockets.
 
if the game isn't running and it's a single color screen it means the daughterboard needs to be reseated. taking it out is kind of a delicate process, you never want to pull anything out one sided. you have to progressively work either side until it comes free. then plug it back in. the outer single wipe sockets on Nintendo boards are a tricky art. a module like Dr. Mario runs on will not work with machine pin or dual wipe sockets, the pins are too large, so you have to just live with Nintendo sockets.
I had another thought if reseating doesn't fix it. Scorched LM3900 meanes someone reversed the EZ20 amp plugs. Audio on the VS System is generated by the 2A03 CPU and there isn't much between the audio out and the LM3900s. So there is a slim chance if the user got unlucky and the reversed plugs also took out the CPU. Just depends on how it failed.
 
Back
Top Bottom