what could cause these errors with my boards? ram error and z-80 error??

NGT

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well, I am making a bartop setup and got it all wired up. the monitor seems to have a loose power connection on the board and I touch the wires and to goes off.

Other then that, no clue.


here's what happend....I hook up a one slot and it works but is really "yellow" in the picture...so I turn it off and back on and then a z80 error. So I mess around with it and and popped in a board that I use for testing....it's yellowed and after a second boot up...I get a ram error...


so basically I just fucked myself out of $120 bucks or so....I am really pissed off and want to throw this thing out the fucking window..


anyways...any idea on what could possibly case this to happen to my games?
 
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NGT

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fixed the loose wires from the monitor....but it's still yellow and I don't see any change when I adjust the blue from the rgb....

the crime city game came back....but the one slot is still z-80 error...

any idea on the cause? or a fix for the z-80 error?
 

NGT

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Switched the powersupplies and I still get a bunch of yellow....and a ram error on my crime city again.


still looking for thoughts on the z80 error :(
 

chris1

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Anytime I ever got a Z80 Error it was because of dirty carts or dirty motherboard connectors..This before I started to clean my carts real well before putting them in..(and mb)

IMO a Z80 shows up when you have a bad connection..something's dirty.
Clean the harness pins real good and the edge connector.(worth a shot)

I forget but I think the Z80 refers to the sound chip..
 

chris1

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I did a search for Z80 Error but didn't come up with much for the issue at hand.

http://www.neo-geo.com/forums/showthread.php?t=99361&highlight=Z80+Error
The Z80 works in conjunction with the YM2610 sound processor.
There is a watchdog within the Z80, which monitors any problems with addresses/interrupts, which will lead to the error message.
The no sound may be a red herring, usually an error message would appear (rather than the game run with no sound) with Z80 problems afaik.
Ive had problems with intermittent connection around the Z80, there is also the SM1 rom and 6116 ram chips associated with the processor, problem turned out to be dry joints and open circuit tracks. Run some solder on the IC pins, remember there is a layer of tracks sandwiched in the centre of these boards, they are not simply double sided so you may not see anything apparent. I dont think the Z80 or associated memory would be at fault.
Very vague I know, anyway good luck.
 

NGT

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the thing I don't get is....why would I have a ram error on a jamma board the second after getting the z80 error on my one slot? It couldn't be dirty connects on the mvs board....it happend to two things. It has to be wiring....but now the crime city game plays, while I continue to get the z80 error on the one slot. Then, what's up with the yellow picture and no blue?

any ideas? I am lost
 

NGT

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come on man...I see this error all the time and nobody has a fix...?

HELP!!!
 

NGT

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another thing I noticed about the monitor and every once in a while the yellow part that should be white will flash white...like letters etc...and a bit of blue will pop up here and there. Then go right back to yellow with no blue.
 

Razoola

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I dont quite understand the setup you have. Are you saying that the MVS works fine in a different cab but dosent work fine in this new cab?

Raz
 

NGT

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^^it did work 100% until the third time I booted it up in the bartop game. Now it's z80 all the time...nomatter what it's hooked into.

I am making a neo bartop game...


I put the game in and it worked fine but there was no blue in the monitor and everything was very yellow looking.

The sound was low...

I powered up the board again and got a z80 error on the one slot.

Everything in the cab is wired via jamma for the one slot.

I put in a crime city jamma board and it worked, but same monitor problem (yellow etc)

then, that board got a ram error.

So...I tried another power supply and I get the same thing.


I do have a transformer for the monitor in there...



The crime city game came back and works, but went out with a ram error again..then it sat and worked again....same problems though.


The one slot now gets the z80 error nomatter what I hook it up to. Cab/supergun/ etc....


what could cause this? Power wiring? bad monitor? Could I have shorted out the audio amp?

I just need ideas for testing so I can get it right and if someone knows how to fiz the z80 error so I can get my one slot back and running, that would be an added bonus.

The power wired are going through a couple different molex adapters...could that be messing it up?

I just don't know what the problem is...


that's pretty much where I stand right now.....z80 error on the one slot....no blue on the monitor and bits of blue and white popping in and out...ram error on the crime city pcb, but that board comes back after some rest....but the one slot hasn't worked on anything else...

any ideas?
 

NGT

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right now, I would rather have my 1 slot back then get the bartop working....

any ideas on fixing a z80 error?


I turn it on...and it says z80 error...that's it.....

any ideas?
 

Razoola

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No idea what happened there but it does sound like something on this new cab messed something. There are a number of things that can cause a z80 error like faulty z80 bios, faulty z80 chip, dirty cart contacts or problems in the port that links the z80 to the 68k. What MVS model is it btw?

Raz
 

NGT

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It's an mv-1fz...

I am sure something in this wiring is screwing everything up. For some reason I think it has to do with the AC/L and the AC/N maybe getting crossed on something... I am not 100%, but it's been running through my mind all day and that's the only part of the wiring that I am not 100% sure everything is in the correct spot.

Everything else is right....I am 99% on that.
 

Razoola

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Could maybe be a grounding issue or something.

Raz
 

NGT

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checked the video and rewired that and still all yellow screen when it powers on with no game. It should be blue right?

I get no blue change when I mess with the dial...

The only thing I can think of is the power wiring....



oh, and the monitor is grounded...

I don't have the transformer grounded on the outside...could that be the problem.
 
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