MV-1C Calender Error

Pasky

Fug:DDDDD,
Joined
May 5, 2013
Posts
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Battery is removed.
Crystal has a 32Mhz sine wave.
NEC D4990A is getting +4.3V on power on (this seems normal, my other MV-1C gets this as well and boots fine to the cross hatch).

Neo MV-1C keeps getting stuck at green screen boot, very rarely comes up with black screen saying Calender Error. I can't get the black screen anymore but it was doing it more often when it first began.

Using a Uni-bios 3.1 free version it bypasses the error and I can boot to a game.

I'm thinking its probably the D4990A itself. I don't see any damaged traces around the NEC chip anywhere. Anything else I should check on the chip to rule it out before considering it's bad?

Just looking for other tech opinions before I try to replace it.

Thanks.
 

GadgetUK

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Joined
Sep 27, 2013
Posts
1,323
Battery is removed.
Crystal has a 32Mhz sine wave.
NEC D4990A is getting +4.3V on power on (this seems normal, my other MV-1C gets this as well and boots fine to the cross hatch).

Neo MV-1C keeps getting stuck at green screen boot, very rarely comes up with black screen saying Calender Error. I can't get the black screen anymore but it was doing it more often when it first began.

Using a Uni-bios 3.1 free version it bypasses the error and I can boot to a game.

I'm thinking its probably the D4990A itself. I don't see any damaged traces around the NEC chip anywhere. Anything else I should check on the chip to rule it out before considering it's bad?

Just looking for other tech opinions before I try to replace it.

Thanks.

If the traces are OK, I would just swap it out. You could stick SMK Dan diagnostic BIOS in there and run the calendar test but I am guessing it will just sit there waiting for pulses.
 

Pasky

Fug:DDDDD,
Joined
May 5, 2013
Posts
2,844
Know where to get SMD 16 pin variant of the D4990A? Can only find the DIP 16.
 

GadgetUK

Ace Ghost Pilot
Joined
Sep 27, 2013
Posts
1,323
Know where to get SMD 16 pin variant of the D4990A? Can only find the DIP 16.

I would love to know the answer to this too lol! Only place I know of atm is another faulty board =/
 
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