MVS Puzzle De Pon Graphic corruption. Which chip Do I replace?

[pierpa86]

Lift a pin

Here an example for 27c160 to 27c800 use...
Last address pin to GND

 

[neofan]

I connected A18 to ground. Still the same screen.

 

[neofan]

I have a 27C400 as P1, although my board is a PROG 4096.

I think you're right. 2020 baseball uses a 27c400 for a 512kb P1 on a 42g-1. I ordered a few today. If it doesn't work I'll just convert it back to vanilla.

 

[pierpa86]

I think you're right. 2020 baseball uses a 27c400 for a 512kb P1 on a 42g-1. I ordered a few today. If it doesn't work I'll just convert it back to vanilla.

Yes, 27c400 have same pinout of 27c4100.
Its wird that grounding last pin and double p1 on 27c800 doesnt work.
i always do that, what crc of your p1 ? i dont have at moment a prog 42g-1 so i cant test it on.

 

[neofan]

I programmed a 27c400 equivalent chip and it's working now. Thanks for the help