green screen during z80 test with diag bios and cart

Hi, i am always stuck with an 1fz that i resurrected from dead (it was in watchdog mode), i swapped z80 and it worked but sound stopped working again. i desoldered and socketed ram11, sm1 and ym2610, when i use its original ym2610 i have expected c3, actual d3 with z80 dead/comm. error but when i use a new ym2610 the screen became green when i press start+pause keeping D pressed.

The diag bios uses the FIX layer tiles to display text on screen. When enabling the z80 test, the diag bios has to switch to the cart slot, which causes FIX layer tiles to switch from being sourced from SFIX (on the mainboard) to the S1 rom (on the cart). If there is an issue pulling data from the S1 rom you can get graphic issues and/or no graphics at all in the diag bios. So make sure your cart/slot are clean, the slot board itself is fully seated in the mv1fz mainboard, and that your cart isnt at a bad angle because you don't have the plastic cover on.

thanks.with new 2610 i have actual:d3 also this z80 is broken.....

The difference between actual: D3 and expected: C3, is one bit. Specifically bit 4 is high when it shouldn't be. Perhaps check the data pins from the z80 to neo-c1 and from neo-c1 to the 68k

ack said:

The difference between actual: D3 and expected: C3, is one bit. Specifically bit 4 is high when it shouldn't be. Perhaps check the data pins from the z80 to neo-c1 and from neo-c1 to the 68k

Click to expand...

i checked:
68000 (65) - c1 (49)
68000 (64) - c1 (50)
68000 (63) - c1 (51)
68000 (62) - c1 (52)
68000 (61) - c1 (55)
68000 (60) - c1 (56)
68000 (59) - c1 (57)
68000 (68) - c1 (58)

on the z80 side
z80 (7) - c1 (80)
z80 (8) - c1 (77)
z80 (9) - c1 (81)
z80 (10) - c1 (82)
z80 (12) - c1 (76)
z80 (13) - c1 (83)
z80 (14) - c1 (74)
z80 (15) - c1 (75)