Dead MV-1FZ

Codeman1

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Thats right... my MVS is dead <img src="http://www.neo-geo.com/ubb/icons/icon20.gif" alt=" - " />

In <a href="http://www.neo-geo.com/ubb/ultimatebb.php?ubb=get_topic;f=5;t=004323" target="_blank">this</a> thread there is an MVS with the same symptoms.

Here's a pic of my PCB--> <a href="http://megacromos.home.sapo.pt/DSCF0043.JPG" target="_blank">328 Kb</a>

Mine gets stuck at the green h/w test, seems as if it reboots and does the test over and over again. I think its the same problem that kernow has.

No diference if it has any cart or not, I even tried putting my old BIOS back (I have the UNI-BIOS) but it has the exact same symptoms.

I didnt do anything special, I had played a few hours before it stoped working, then I wanted to try out a new pad I hacked for my supergun and then my MVS didnt boot.
Im pretty sure that the pad wasnt the problem, I probed it and there are no shorts, maybe it was just coincidence :rolleyes:

I think the battery may be dead but I dont think that would make any difference... would it? spock

If I put all the Dip-swichtes on I get this:

BACKUP RAM ERROR

ADDRESS WRITE READ
00D00010 5555 4241


(I think before swapping the BIOS I had a different ADDRESS and READ value...)

Please help help help !
Any ideas? Any suggestions?

BTW did kernow ever get his MVS to work?

<small>[ April 20, 2003, 04:52 PM: Message edited by: Codeman1 ]</small>
 

kernow

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Mines not working yet no.. its a backup RAM error like yours, but obviously a different code.
 

Atro

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coincidences ?

Man, how can such a piece of hardware can die like that ?

It's basicly the same as an AES, I'm affraid to face such an issue like this too now. :mad:
 

Razoola

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Codeman1:
BACKUP RAM ERROR

ADDRESS WRITE READ
00D00010 5555 4241
This is a very very strange value to get. Basically 0x4241 at 0xd00010 is the normal value held at this address. I just wonder if the problem is more related to the backup ram protection flag (basically memory is not written to unless this flag is first set).

Its also possible due to the error numbers you are getting that your RAM has had a problem for a while but the situation has only just started to show itsself (a backup ram test never happens unless all hardDIPs are on or the memory header is bad / missing.

I personally feel you may beable to fix your issue by giving your PCB a good clean if your lucky.

Raz
 

kernow

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Razoola:
Codeman1:
BACKUP RAM ERROR

ADDRESS WRITE READ
00D00010 5555 4241
This is a very very strange value to get. Basically 0x4241 at 0xd00010 is the normal value held at this address. I just wonder if the problem is more related to the backup ram protection flag (basically memory is not written to unless this flag is first set).

Its also possible due to the error numbers you are getting that your RAM has had a problem for a while but the situation has only just started to show itsself (a backup ram test never happens unless all hardDIPs are on or the memory header is bad / missing.

I personally feel you may beable to fix your issue by giving your PCB a good clean if your lucky.

Raz
Cleaning is good, I've yet to give mine the 2nd over.
 

Codeman1

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Razoola:
Codeman1:
BACKUP RAM ERROR

ADDRESS WRITE READ
00D00010 5555 4241
This is a very very strange value to get. Basically 0x4241 at 0xd00010 is the normal value held at this address. I just wonder if the problem is more related to the backup ram protection flag (basically memory is not written to unless this flag is first set).

Its also possible due to the error numbers you are getting that your RAM has had a problem for a while but the situation has only just started to show itsself (a backup ram test never happens unless all hardDIPs are on or the memory header is bad / missing.

I personally feel you may beable to fix your issue by giving your PCB a good clean if your lucky.

Raz
I think it used to have a different address and value before...
Anyway this only happens when I put all the hardDIPS on, with the hardDIPS off it just does the h/w test and reboots like mentioned in my other post.

Lets not be distracted from the main problem kernow, the problem you have on your board is the same as mine(stuck at h/w test screen), right?
Are these problems related?
Can a backup memory error/dead battery cause similar symptoms and/or prevent an MVS from booting?

I made a small <a href="http://megacromos.home.sapo.pt/mv1fz.avi" target="_blank">video</a> capture of the problem. (Divx 5.03 video)

About the PCB cleaning, how will cleaning it make it any better? spock
 

ttooddddyy

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I have found that a slightly low 5 Volts vcc can cause these sorts of problems, 5.2 volts seems to be the best setting for my MVH6s.
Hopefully it may be as simple as that. You will need an accurate meter as its quite a critical setting. More so than with most jamma boards in my experience.
 

Codeman1

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ttooddddyy:
I have found that a slightly low 5 Volts vcc can cause these sorts of problems, 5.2 volts seems to be the best setting for my MVH6s.
Hopefully it may be as simple as that. You will need an accurate meter as its quite a critical setting. More so than with most jamma boards in my experience.
I forgot to mention that was the 2nd thing I checked after swaping the BIOS, it reads exactly 5.2V, I'm using a PC AT power supply btw.
 

Atro

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Where's Nightmare Tony ?? eye eye

Maybe Jeff Kurtz could help here too, but he rarely shows himself up lately. frown
 

ttooddddyy

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Yes, infact Ive seen boards that have a a limit switch fitted to do just that.
Dis the battery and damp the supply to reset the back up.
 

Nightmare Tony

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Atrophied: was out in vegas at a haunted house trade show. Gklad top be back home in the country, the city fumes are just %$#@^%$#@^%@!

For the wierd RAM error, I find that anything with the enable or read/write lines would cause that, the ram is basically behaving wildly. The backup ram is battery based, so make sure to keep that voltage going, at least 3 volts from it. Usually, a dead battery would cause a calendar error first.

Check and see if there is corrosion around the battery backup rams. There are 6 flatpack rams, only 2 of them will have battery voltage on pin 24 when the board is disconnected. Those are your two battery rams. Find a datasheet on the 62256 RAM chip, and that pinout will be correct yto look at the enables.

Sadly, some boards that get that error I have never been able to fix. but for the ones I do, the hints above may help...
 

Codeman1

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Nightmare Tony:
Atrophied: was out in vegas at a haunted house trade show. Gklad top be back home in the country, the city fumes are just %$#@^%$#@^%@!

For the wierd RAM error, I find that anything with the enable or read/write lines would cause that, the ram is basically behaving wildly. The backup ram is battery based, so make sure to keep that voltage going, at least 3 volts from it. Usually, a dead battery would cause a calendar error first.

Check and see if there is corrosion around the battery backup rams. There are 6 flatpack rams, only 2 of them will have battery voltage on pin 24 when the board is disconnected. Those are your two battery rams. Find a datasheet on the 62256 RAM chip, and that pinout will be correct yto look at the enables.

Sadly, some boards that get that error I have never been able to fix. but for the ones I do, the hints above may help...
Welcome back Tony!

The battery has lost its charge now but the same problem still happens.

There doesnt seem to be any problem with corrosion/etc as you can see <a href="http://megacromos.home.sapo.pt/DSCF0043.JPG" target="_blank">here</a> .

Those 2 RAM's should be the 2 big chips inside the white outline of the backup area, right?

Anyway to test them to see if they are working right? (since the battery is dead now I cant check the pins for voltage)

Could those other 2 small chips inside the backup area give similar problems? I once saw a repaired PCB with one of those replaced so...


Another thing that I was wondering (In case you didnt all the above posts), are these 2 problems related?
My MVS just keeps doing the h/w test, it only gives that error when I put all the hardDIPS on.

We are all wondering about that backup error and forgetting the main symptom...
 

Codeman1

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BUMP!

Almost 2 months without playing my NeoGeo <img src="http://www.neo-geo.com/ubb/icons/icon20.gif" alt=" - " />
 
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