MV1FZ cyan screen on boot

[Jarryson]

Hi all,

I am repairing a MV1FZ 1 slot and it have a strange issue. I saw the same problem in this forum but without solution.

When I power on the board, it show a cyan screen. If all dips are ON screen is purple.

No crosshatch screen.

If I insert a game, game works fine, if dip 1 is On with game inserted I can do a hardware test.

Board cleaned, no chips replaced or bad traces (I think). Only D0 replaced but same issue.

Neo Diagnosis Bios tested and all tests passed.

Tested with other Original bios (SP2) and same result, cyan screen.

 

[Xian Xi]

Check the resistors on the hard dips and the traces to the F0 chip.

 

[Jarryson]

Check the resistors on the hard dips and the traces to the F0 chip.

Hi Xian,

I will check the F0, but, in other post from 2013 "fremen" had the same problem and you said maybe the problem is D0. I replaced D0 and no lucky.

 

[Xian Xi]

So you have to text on the screen except if a cart is inserted?

 

[Jarryson]

So you have to text on the screen except if a cart is inserted?

Without cart inserted:
- (static) cyan screen
- If neo diag bios installed , purple (static) screen
- Dips doesnt work

With cart inserted:
- game works fine, sound, graphics, texts, all...
- if neo diag bios installed, "All Tests passed"
- if Dip 1 is ON I can see the game menu, Hardware test included.

TESTED:
- Neo-D0 replaced, no lucky
- No bad traces, I have checked all traces between 68K, work rams, system rom...

 

[Xian Xi]

Check the SFIX rom, an FZ won't need a cart to display text if the SFIX rom is working correctly.

 

[Jarryson]

Check the SFIX rom, an FZ won't need a cart to display text if the SFIX rom is working correctly.

Ok, I have desoldered SFIX and traces are OK. This afternoon I will replace this chip by other.

EDIT: Board repaired, thanks for all Xian.