MK II rom problem {anyone help me}

Danimal219

New member
Joined
Jul 11, 2010
Messages
627
Reaction score
2
Location
Portage 46368, Indiana
I'm getting a bad custom rom at UE13. This is the older MKII board that has the sister board connected to it. The UE13 is the main socketed Rom on the main board is this Fixable, and if so can anyone help me? Mine looks to have the rev. 3.1 in it did the older boards come with rev. 3.1 or could the 3.1 chips been added and cause this error? also don't know if this matters both my #8 dips are on and thats it the rest are off




here's a link to pictures of the boardset type
http://www.hobbyroms.com/MK2.html
 
Last edited:
greetings sir. speaking as someone with a MK2 board that's been nothing but a fucking headache, I might be able to offer you some pointers on what to try.

the first thing to note, according to board repair gurus like channelmanic, that the surface mounted chips on these boards are prone to the legs breaking and other similar anomalies. I can't fix that, and I'm going to assume you can't either, cause you have to be a soldering wizard to fix that.

I used to get CUSTOM CHIP BAD errors on startup as well, along with an assortment of baby crying sounds and other incorrect sounds. the sound board would also return a SOUND IRQ NOT DETECTED error, despite the sound working.

over the years, I've noticed other people have had the same problem, and no amount of messing with it got it to work right. based on my experience with a DK board that would lock up and do other sorts of strange shit, I found that the socketed chips on it had a dark corrosion on them, and after sanding the chip legs the game worked again.

I don't run my MK2 board ever, so I wasn't ever aware of its condition. turns out, the game roms on it (the 3.1 roms, not the graphics or sound roms) actually had a lot of corrosion on them. after sanding them, the Custom Chip problem went away.

another problem cropped up, but I think I fixed that too (one of the socketed CPU chips had a broken socket that wasn't making good contact with the chip -- quick fix was tying a ziptie around it very tight)

the other thing to check of course is your +5 voltage, but I doubt that's the case here -- that would only really cause the game to not boot at all or reset.

if you have any other questions don't hesitate to PM me about them. :)
 
U13 is a 27C040 or 27C4001, but what speed? Is it a -12 or -10?

I have the ROM images. They aren't available in MAME but another forum member sent me a 4Mb ROM version board (the one with the daughterboard) once to copy the ROMs off to fix another board for someone.

I'd love for it to eventually be put in the MAME archives.

Anyway, back to your issue, I can program a ROM and send it to you for a nominal cost.

RJ
 
The UE13 is the surface mounted chip I'm having the error with! Sorry made error on the post! Well after looking at one of the main socketed chips it has the revision 2.11 sticker on it and the other one does not. I'm assuming both are 2.11
Could having 2.11 with the 3.1 roms in UJ12 &UG12 make errors with the surface mounted chip? Is there anything I can do with the dips? Ie. further rom testing? any help is appreciated!

The main socketed chips are both texas instruments and read as follows on chips!
1st chip
31500SWBL
TPC1020AFN-084C




2nd

TMS34010FNL-50
WEU9324
3105036
 
Is it the TPC1020AFN that you are talking about being bad?

Unfortunately the data sheet says that chip is a Field Programmable Gate Array. That is a chip that is only available off another board.

If that's what's at UE13, then it's the system DMA controller. If you have problems with it then you'll get all kinds of screwy errors. I've seen one of those that needed reflowing. Bad solder will cause that chip to show up as bad.

RJ
 
I guess all is fine as in the link it has the same setup with the 2.11 socketed chips with the 3.1 roms at UG12 and UJ12. I'm assuming it's the bad surface mount chip is bad i checked some traces and i'm no pro and I'm wondering if this is fixable if it is the surface mount chip!
 
If it's not a reflow issue (bad solder) then it's a bad chip and the only source is another MKII board or a board from the same family (Midway T unit)...

RJ
 
I had a similar problem with one of my MK2s once, i ended up popping out the socketed square chip (don't remember location but its the only square socket on the board) and after that was reset it did fix the various rom errors including the UE13 problem one you are talking about. MK boards are otherwise disposable to me. I was eating lunch watching the attract mode one day and it just died like that right there, pretty bad. lol
 
You need a PLCC chip puller to pull that chip out of its socket without cracking the socket. That socket is terribly easy to break if you use a screwdriver.
 
You need a PLCC chip puller to pull that chip out of its socket without cracking the socket. That socket is terribly easy to break if you use a screwdriver.

^ what he said.

*whistles*

now that's why I have a ziptie around my chip socket. :)
 
Back
Top Bottom