TheJeffChen
n00b
- Joined
- Jan 20, 2020
- Posts
- 7
This MV1ACH board came in in very bad shape (missing caps and scratched traces on the bottom) and was not even booting. I fixed all those and it's now at least booting my 161 in 1 cart.
However, it keeps resetting when playing almost all the games. I put in a Unibios and kept getting all sorts of errors.
Mostly:
- Illegal instructions
- Address error read/write
Some example of broken graphics:
Samurai Shodown 4's title screen sprites gets squished horizontally. Some other text sprites are also squashed horizontally. There was one case I was wiggling the board and the sprites actually changed width live.
Last sword gets totally scrambled image on the background.
I have a working MV1A and switched the cartridge board, but there was no improvement.
Interestingly, World Heroes plays totally fine. Neo DriftOut plays fine until the race is over.
I put the board into RAM test and the screen only shows "MAIN RAM TEST" even after 45 mins.
I burnt a diagnostic BIOS and all tests were passed.
I tried switching the two video chips (RAM 5&6) and nothing changed.
The thing I'm not sure are the missing SMD capacitors. I didn't know how big they should be so I put 100nF on all the missing ones.
Other than that, I'm suspecting this might be a bad CPU.
Please shed some light. Thank you guys!
However, it keeps resetting when playing almost all the games. I put in a Unibios and kept getting all sorts of errors.
Mostly:
- Illegal instructions
- Address error read/write
Some example of broken graphics:
Samurai Shodown 4's title screen sprites gets squished horizontally. Some other text sprites are also squashed horizontally. There was one case I was wiggling the board and the sprites actually changed width live.
Last sword gets totally scrambled image on the background.
I have a working MV1A and switched the cartridge board, but there was no improvement.
Interestingly, World Heroes plays totally fine. Neo DriftOut plays fine until the race is over.
I put the board into RAM test and the screen only shows "MAIN RAM TEST" even after 45 mins.
I burnt a diagnostic BIOS and all tests were passed.
I tried switching the two video chips (RAM 5&6) and nothing changed.
The thing I'm not sure are the missing SMD capacitors. I didn't know how big they should be so I put 100nF on all the missing ones.
Other than that, I'm suspecting this might be a bad CPU.
Please shed some light. Thank you guys!