Neo Geo MVS MV-1A - Pink Screen

RyuX

Crossed Swords Squire
Joined
Sep 19, 2018
Posts
179
Hey guys.

I recently purchased a broken MV-1A.
It looked pretty good - no battery leak - quite clean but I only get a Pink Screen.

When pushing around the board the color might change but ultimately I can never get through even with the diagnostic bios.

I measured some of the Caps and got only 500 Ohms from 5V to Ground - not sure if this is normal for this board.

Maybe anyone had a similar issue ?
I just want to ask around before I start replacing the RAM Chips etc. until I can get it to post into the diagnostic rom.

Thanks guys.
 

RyuX

Crossed Swords Squire
Joined
Sep 19, 2018
Posts
179
Hey there..

Well little did I know what was ahead of me...
I replace all the RAM Chips - the CPU - check all traces and replaced every other chip imaginable except for the NEO-BUF (because I have none).
So I switched NEO-BUFs around from one position to another and now I am able to get at least a watchdog response.
Man these M1A Boards suck.
Any cheap way to get NEO-BUFs ?

121184243-325101702119732-4582477551649891654-n.jpg
 

DaisyAge

Galford's Armourer
Joined
Jun 10, 2018
Posts
457
Hey there..

Well little did I know what was ahead of me...
I replace all the RAM Chips - the CPU - check all traces and replaced every other chip imaginable except for the NEO-BUF (because I have none).
So I switched NEO-BUFs around from one position to another and now I am able to get at least a watchdog response.
Man these M1A Boards suck.
Any cheap way to get NEO-BUFs ?

121184243-325101702119732-4582477551649891654-n.jpg

https://www.tindie.com/products/furrtek/neo-buf-replacement/
Best one there is
 

RyuX

Crossed Swords Squire
Joined
Sep 19, 2018
Posts
179
Hey.. Yeah I found these on google before as well. Still have to decide if I want to invest into this board or rather keep it as a spare part donor for my Neo Geo CD. Anyways ordering a couple of NEO-BUFs won't hurt.
 

RyuX

Crossed Swords Squire
Joined
Sep 19, 2018
Posts
179
Bad Luck as of now.. I replaced all of the NEO-BUFs with the Furrtek Replacements but first still got a similar Watchdog and now currently I am back to a all WHITE Screen.
So decided to change back the 68k to the original one - same result.

Currently giving it a dishwasher treatment and will then dry it properly and troubleshoot again and post some pictures of the current state :(
 

RyuX

Crossed Swords Squire
Joined
Sep 19, 2018
Posts
179
So as of right now I replaced all the RAM.. swapped around all of the LS / HC ICs with spares and cleaned the board really well.. all of the NEO-BUFs are new but still.. the board seems dead.
I inspected all of the traces and also can't find any corrosion or broken traces or short circuits anywhere.

122588056_777496976432230_3558870027748725635_n.jpg

At the moment I get this when turning on.
Not sure if this is supposed to mean that the CPU is ok or not - this is getting depressing (like almost every other Neo Geo Repair I had previously. lol)


Any hints or someone had something similar on theirs ?
 

RyuX

Crossed Swords Squire
Joined
Sep 19, 2018
Posts
179
and after just half an hour... back to the pink screen I had in the first place.

So the problem might not be related to any of the parts that I replaced.
Since the pink screen is stuck I have no watchdog active.

Feeling a little like giving up at this point. I have no spares of the bigger packages like the MGA or GRC

122475994_2113050192159911_2169372209899555615_n.jpg
 

RyuX

Crossed Swords Squire
Joined
Sep 19, 2018
Posts
179
Always very sad when this happens.. only had 2 Boards that I wasn't able to fix yet and it always goes into the box of shame.
I just don't have enough proven working spare parts I guess. Well - this board still is good as a donor for my Neo Geo CD, at least that.
 

DaisyAge

Galford's Armourer
Joined
Jun 10, 2018
Posts
457
FWIW I have an MV1FZS for parts I can I send you for cost of shipping. It's missing the 68k and a few pallette ram chips but everything else is there
 

RyuX

Crossed Swords Squire
Joined
Sep 19, 2018
Posts
179
Thank you for your kind offer. How much would shipping of the PCB alone be to Austria / Europe ? I Guess it would be quite expensive ?
 

DaisyAge

Galford's Armourer
Joined
Jun 10, 2018
Posts
457
Oh I didn't even realize you were in Europe. Yeah honestly buying board off ebay or aliexpress would be cheaper.
 
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