Neo Geo MVS "Calendar Error"

[Dangerboy]

Anyone have an answer on how to know the specific problem with an MVS 2 Slot board that gives the error screen "Calendar Error"?

I've done some research and can't find any concrete solutions, though there seems to be three possibilities:

a. The back up battery is dead (needs replacement or modded out)
b. A PCB Rom is dead
c. A connection line (tracer?) is cut

Some entries say a battery replacement is the fix, or that the Unibois would circumvent the check. Anyone know of a sure fire way to know the issue for those of us with no technical experience at all?

[JohnnyA]

Did you clear the backup ram?

[Dangerboy]

I flipped all the Dip Switches and got "WORK RAM TEST". Returned all dip switches to normal, got Calendar Error again.

How does one clear the RAM?

It should be noted that the error message won't allow me to get to test mode via the test button. Is there a dip switch setting I can use?

[Dangerboy]

Actually...i held ABC and reset the machine, and now I get:

Color RAM BANK0 Error
Address Write Read
0040012C 012c AAAA

I think this is a dead duck -___-

[aclbandit]

Actually...i held ABC and reset the machine, and now I get:

Color RAM BANK0 Error
Address Write Read
0040012C 012c AAAA

I think this is a dead duck -___-

Well... I searched a bit and found this: http://www.neo-geo.com/forums/showthread.php?t=73917

Have you tried cleaning the cartridge connectors and/or a different cartridge? Just to be sure that that particular possibility is taken care of...

[Dangerboy]

The cartridges aren't the problem. They all work fine on my 1 Slot.

The "Calendar Error" comes up as the default screen, with empty cart slots. In reality, an empty PCB should display a white grid test screen, which would then allow you to go into the PCB settings. I can't even get to that.

If it's just the battery, it'd be a $4 fix with soldering, but I've never soldered before.

Haven't been able to find genuine 'error' list, as the MVS manuals are junk.

[channelmaniac]

Hey folks,

Calendar error is either a bad Clock/Calendar chip (VERY unlikely), a bad 32.768khz crystal (likely) or no +5v on the chip when powered up (VERY likely).

The "no +5v" is caused by corrosion on the board from a leaky battery.

Crystal can just be a dead crystal or one killed by a leaking battery.

I've also see that message come from gouged traces on the bottom of the board.

Calendar Error is also known as "Stuck on Green Screen" when starting. Both signify a calendar problem.

Bad Color RAM is one or more bad 8464 (64k x 8) SRAM chips. It can also be a bad 74LS273 on the color outputs, a bad 74LS244 buffer chip, or a bad NEO-G0 chip.

I can fix those problems if you need someone to work on your board. Check my repair logs for more info.

RJ

[Ryaan1234]

Have you tried cleaning the cartridge connectors and/or a different cartridge? Just to be sure that that particular possibility is taken care of...


Have you tried cleaning the cartridge connectors and/or a different cartridge? Just to be sure that that particular possibility is taken care of...

Ummmmm.......?

I guess the French spammer is at it again.

[scooterb23]

Oui Oui.

[Dangerboy]

So just replacing the battery won't do the trick, eh?

I think I'll just resell this one off for parts. I'll use my 1 slot till I can find a better (and working) 2 slot.

[channelmaniac]

I repair these boards for folks and can either repair your board, or buy it so I can repair it and sell it.

Look me up by the same username on the neo-geo.com forums or check my repair logs site.

RJ

[98PaceCar]

I'll vouch for RJ here. He's worked on my MVS board, one of my AES boards, and a couple other random arcade boards I had laying around. Top notch work and they are all still working perfectly.

[blue lander]

Actually...i held ABC and reset the machine, and now I get:

Color RAM BANK0 Error
Address Write Read
0040012C 012c AAAA

I think this is a dead duck -___-

My MVS had the same problem, like channelmaniac mentioned it was a bad color RAM chip. There's instructions somewhere out there on how to track the problem down, but as I recall you basically short out each of the color RAM chips one at a time and see if the address in the error message changes. If it doesn't, you know you shorted out the chip that was already broken. I replaced it with a 55256 or something like that from an old 486 PC montherboard. Worked like a charm

[channelmaniac]

...I've also see that message come from gouged traces on the bottom of the board...

Well, I bought the board as-is from Dangerboy... and it had 9 gouged traces on the bottom of the board.

I fixed 8 of them, had a graphics error on the back slot, then found the 9th trace which fixed that problem.

It's running at 99% now. I just need to tack the kynar wire down and replace the battery to call it 100% done.

RJ

[Dangerboy]

Damn, you're good. :D

What's scary is, I bought the better looking of the two from the seller. I would hate to know what was wrong with the other one the guy had. @_@;;

[channelmaniac]

It took a little while to track down all the traces. ;)

A jeweler's loupe and some 30ga Kynar wire is all it takes. Luckily I have a HUGE spool (>1000 feet) of that wire. I picked it up for less than $5 at a surplus store the last time I was out in Silicon Valley.

RJ