MVS MV-1B Read/Write Error

[Mageta the Lion]

My MVS stopped working:

1. MVS MV-1B
   1. Uni Bios V3.3 via Neo Bios Masta
   2. Worked for Years
2. Got a "Twinkle Star Spirits" conversion
   1. ADK Intro part Works
   2. Mode Select Graphics are garbled
   3. Char select seems fine
   4. Pick Char (Robot) -> Uni Bios throws an error
3. Tried last Cart i played before Aero Fighters 2 (had been some weeks)
   1. Uni Bios Immediately throws an Error on Boot
4. Tried KoF94 (cheapest Game I'm certain works)
   1. Shows beginning of the Intro (Invitation drop) then throws uni bios read error

What did i try:

• Different setups (different psu etc.)
• Different Cards (see above)
• Putting all dips down and let the board run for half an hour without a cart
• "Reseated" (aka. Pusehd down) Uni Bios and Neo Bios Masta (don't think that thing moved, tight fit)

Error Screen Kof94:

Any Tips/Hints what the Issue might be?

 

[ack]

Sounds like a dirty slot or carts. Try using unibios's crc check and see if the carts are giving NG.

 

[NeoRocker]

Check/Change the electrolyte capacitors. On my 1B some of them died e.g. the AC11 was blown up and rusty.

 

[Mageta the Lion]

Didn't have the "chance" to clean the Cartslot yet but checked via the unibios.

• Uni Bios version is 3.2 and not 3.3 as previous claimed.
• Gamecart check gives an OK for KoF94 (which still crashes during the intro)

• The Uni Bios menu is "garbled" (might be just that one screen, the rest i saw was fine)

Can i assume that the Cart slot is fine and the Issue is with the Uni Bios or its installation? Does it make sense to dump the Unibios or would it be completely non working if that was the issue? (Window on the eprom is covered so no partial erase by light)