video ram error

bob2776 · Mar 22, 2005

I' ll try to explain better (newbee) on power up error reads -VIDEO RAM ERROR - address 00000204 write 5555 5505 - sent board to a shop and they said processor is shot and could not be repaired - any thoughts?
I have done some board repairs in the past if i know what to change-HELP! :help:

Razoola · Mar 22, 2005

I don't think the processor is shot, if it was you wouldent even get an error in the first place. More likley one of you RAM chips is faulty.

Raz

bob2776 · Mar 22, 2005

Razoola said:
I don't think the processor is shot, if it was you wouldent even get an error in the first place. More likley one of you RAM chips is faulty.

Raz

that's what I thought so any ideas how to find out which ram or if not who i might be able to send board to for repair who knows what thier doing - also i do have an original single slot any chances of swapping rams for diagnosis

Adamaki · Mar 23, 2005

That sounds similar to a faulty board that's being sold on ebay at the moment. http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=8178078986&ssPageName=STRK:MEWA:IT

Is this a faulty ram chip as well? It looks beyond my mediocre skills anyway!

bob2776 · Mar 23, 2005

Adamaki said:
That sounds similar to a faulty board that's being sold on ebay at the moment. http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=8178078986&ssPageName=STRK:MEWA:IT

Is this a faulty ram chip as well? It looks beyond my mediocre skills anyway!

apparently this is a very common problem - my address 00000204 is different and the word read does not appear above the5505 error also mine is an original 4 slot but all these errors aparently tie into the fact that snk tried to way out do the graphics before thier time thus all the video ram problems - still looking for someone who can id ram and if it's even available. i am also willing to send off board for repair if some really can do it.

dogtoy · Mar 25, 2005

bob2776 said:
apparently this is a very common problem - my address 00000204 is different QUOTE]

That is sort of an odd address for a Video Ram Error. Is this address even in the same range as the video ram? I suppose the whole first 32K of addressing space are video ram. 2 x 16k ram chips.

I would try jumping pin 11 and 12 together on each chip one at a time to see which one it is (the read number will change to 5500 or 0055) I recently did this with my 4 slot and only had to replace 1 chip (socket there for future problems). It is the two 24 pin PDIP ram chips marked 5814 on bottom board of a 4 slot. Right near CN3, CN4, and CN5.

I'd get a universe bios before I did anything so I could boot past this error and make sure there weren't any other more serious errors. I just bought an mv-1a on ebay w/ pallette ram 1 error thinking i'd just replace the pallette ram and sell it, put in the uni-bios and pallete 1, pallete 2, calendar chip, and z80 communication errors. Yuck!~!

MKL · Mar 25, 2005

dogtoy said:
bob2776 said:

apparently this is a very common problem - my address 00000204 is different QUOTE]

That is sort of an odd address for a Video Ram Error. Is this address even in the same range as the video ram? I suppose the whole first 32K of addressing space are video ram. 2 x 16k ram chips.

I would try jumping pin 11 and 12 together on each chip one at a time to see which one it is (the read number will change to 5500 or 0055) I recently did this with my 4 slot and only had to replace 1 chip (socket there for future problems). It is the two 24 pin PDIP ram chips marked 5814 on bottom board of a 4 slot.

Click to expand...

No, the 5814's give the 8000 error which it's not his case. He'll have to look at the CXK58257 flatpacks (same as work and backup ram).

dogtoy · Mar 25, 2005

Is that the slow video ram? When these go out does the BIOS report Video Ram Error? I thought the error message would be different, like a color pallette error or something for all the flat pak rams. That would make sense though because the address given was way below 8000.

So just ignore what I said above and do what MKL said.

These are going to be a little tougher to replace because they are mounted on the top of the board and not through the board. I'd look good and hard for cut traces before I tried replacing them.

Iain · Mar 25, 2005

I like a challenge ....

Hi,

apologies for any mistakes as this is my first post !

Had a look at the ebay link above and realised that it is the one I have just won !!

First neo geo board for me (collect arcade boards) ... and I like a challenge so if it is of any help I can document what I have to do to this one to get it working ....

Luckily I work at a hybrid electronics factory so have access to various pieces of equipment that should help ....

Hopefully be able to post shortly and help others .....

and a belated hi to everyone as well !

Iain

MKL · Mar 25, 2005

Iain said:
Hi,

apologies for any mistakes as this is my first post !

Had a look at the ebay link above and realised that it is the one I have just won !!

First neo geo board for me (collect arcade boards) ... and I like a challenge so if it is of any help I can document what I have to do to this one to get it working ....

Luckily I work at a hybrid electronics factory so have access to various pieces of equipment that should help ....

Hopefully be able to post shortly and help others .....

and a belated hi to everyone as well !

Iain

If I can read the error message correctly the bad ram chip is the one connected to the higher data lines (pins 54-61) of the CPU. The other chip should be good.
And take notice of this:

http://www.neo-geo.com/forums/showpost.php?p=1450617&postcount=8

Iain · Mar 25, 2005

Thanks for the tip !!

Will take that one out and test first !

If worse comes to the worse I can always make an adapter up for the ram chip ... either mini pcb or possibly a smd socket with the new one soldered on ... will see how well I am off for space on the board !

Better still though may be able to track down a supply of a more compatible chip ... I find the suppliers respond better to a "works request for a small rerun of an old line" than "its a hobby and i would like to buy one or two please ..."

If that is the case will try to grab a few for anyone else that needs them at cost ... again fingers crossed !

Iain

Adamaki · Mar 26, 2005

Iain said:
Had a look at the ebay link above and realised that it is the one I have just won !!

Congratulations on getting a 6-slot for 19 quid! I was thinking about bidding but I don't think I'd be able to fix it, still being fairly new to console modding. Sounds like you're the man to do the job though and if you can get spare chips made that'd be great for the community!

Welcome to neo-geo.com!

Iain · Mar 27, 2005

Thanks !!! Seems very friendly here !!!

Well hopefully I have identified a supplier for the memory chips - that will ship worldwide .... I am just waiting for some info back to confirm the package type ... if they are the right ones they come in at a staggering $2.90 (they only accept us dollars!) with a very low shipping charge !!

If not back to the drawing board ....lol quite literally for an adapter !

Iain

video ram error

bob2776

n00b

Razoola

Divine Hand of the UniBIOS,

bob2776

n00b

Adamaki

Haomaru's Blade Shiner

bob2776

n00b

dogtoy

Haomaru's Blade Shiner

MKL

Basara's Blade Keeper

dogtoy

Haomaru's Blade Shiner

Iain

n00b

MKL

Basara's Blade Keeper

Iain

n00b

Adamaki

Haomaru's Blade Shiner

Iain

n00b