CPS3 scrambled screen

[cma019]

Hello all i would like to request some help on identifying the issue with my board.
I get perfect screen in setting page (like when there is no color) but then in game it will become scrambled
I am sure the cart is fine because i used it on another board. Could it be issue with my Simm? I can complete the flashing though
thankyou very much.

 

[kazuo]

Is this Darksoft BIOS? Seems like the results on the flash SIMM are glitched, but I am assuming 1 & 2 show NG because you have a Darksoft BIOS.

Presumably the CHR RAM is bad? Is there anything obvious going on in that area (corrosion, etc.)?

 

[nonosto]

Check ref about RAM in your MB:

if fujitsu it's ram issue, this chip is avallable in NOS.

 

[GoldenGlover]

Sprite ram is at 1D; character rams are at 2D - 5D. Probably is going to be one of those (2D through 5D) that need replacing.

 

[cma019]

Thanks all, yes it is darksoft custom bios. the simm1 is back to NG after 2nd round of rewriting. looks like i will need to get someone to fix 2D-5D. hopefully i can get it working again.

 

[ShootTheCore]

The flash SIMMs 1 and 2 will always read NG when using the Darksoft image because removing the suicide protections changes the checksums that the game expects in the diagnostic routine.

 

[TheCrow]

The flash SIMMs 1 and 2 will always read NG when using the Darksoft image because removing the suicide protections changes the checksums that the game expects in the diagnostic routine.

Thanks man , i was gonna make a post about it , this saves me time thanks again

 

[cruzlink2]

Before you got swapping onboard ram chips look a the ppu pins. Make sure none are bent shorting or loose.