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Mortal Kombat II arcade help
Ryoshin:
Yesterday I bought a Mortal Kombat II arcade machine. It's not an original it was converted from I don't know what. This is my first arcade machine so please bear with me. The machine powers on fine but it always returns a CMOS invalid error. I replaced the battery today and that did not change anything. Today it also started saying ROM U49 is bad, I cannot find this anywhere on my board, also I don't always get this error. Regardless of the errors it throws up the game still loads up and I am able to play, but there are a few issues. When you insert coins or use the button in the coin door to bypass it at first it will say 1/1 then it'll just get all random like 247/1 etc. Sometimes it will even say 31733 credits needed to play. Also sometimes when the game boots up and you play after every round that you win it will say "1 wins in a row you are the ultimate champion" or something to that effect and asks you to put your name in and the win count resets after every match. Sometimes it does not do this but most of the time it does. I finally figured out how to get into the test menu today, and when I try to restore factory settings it tells me there's failure in the CMOS RAM. I apologize if this is just a bunch of garbled mess, but I don't really know where to start and I've been playing with this thing for the past 12 hours or so. I just finished reseating all the roms on the PCB and the soundboard and it changed nothing. I've also checked the voltages at the PSU and at the JAMMA connector *at least that's what i think it is* and they are fine.
I'm also having a monitor issue. The image on the monitor is too wide. I've played with all of the controls and got it looking great except for this issue as there is no pot for horizontal size. There also seems to be a bad Cap on the board for the monitor as well. I'm very hesitant to mess with that thing it just gives me chills. Supposedly there is some kind of horizontal control that I can tweak with some kind of tool, but I cannot locate it.
Any help would be greatly appreciated, cuz I really don't know what I'm doing, but I have done lots of research the past day or two. I included two pictures that I felt were the most relevent as they are big pictures and there is a limit per post.
Malenko:
I believe U49 is the scratch ram for CMOS. can you change the switch to use dips instead of CMOS?
There's been a couple of posts about a bad U49 on BYOAC before. I usually post first asking if you've changed the dipswitch to use dipswitch settings instead of CMOS and if you've replaced the battery.
As for replacing the U49 scratch ram chip,the part # is:
LH5160-10L
Sharp Japan
9207 7 DC
As for the width, there should be a width adjustment coil, but you'll need a special tool to adjust it (that sort of looks like a plastic allen key)
Ryoshin:
Even when I use dipswitch I still get CMOS errors. The U49 error only shows up every now and then, but you say it's scratch ram, and when in the test menu and I try to reset things it gives me a CMOS RAM Error regardless as to if it says anything about U49 on boot. As for the battery, changing it did nothing. Thank you for the part number for the U49, I believe I know where it's at on the board now. I do believe it has a width adjustment coil, I just can't find it!
EDIT: I'm still having trouble locating that part on my board. Also, do you know the best place I can buy a replacement from? I did a google search but it's coming up with a chip that looks nothing like anything on my board. Thanks again.
EDIT 2: The only Sharp chip on my board is part number LH5268A-10LL Sharp Japan 9323 7D. I assume that's the chip I need to replace. Would I still need to get the part number that you said or try to find this one?
Malenko:
Can you post pix of your board? I doubt its a bootleg, but Id like to see for sure. Also, are your dips set to a country other than USA?
leapinlew:
--- Quote from: Malenko on September 12, 2011, 08:04:52 am ---As for the width, there should be a width adjustment coil, but you'll need a special tool to adjust it (that sort of looks like a plastic allen key)
--- End quote ---
Malenko is telling the truth (Unlike all those times when he is a filthy liar). I actually used a long metal len wrench and while it did heat up, I had about 5-6 minutes before I had to pull it off and let it rest. It didn't take long to adjust but it did take about 15-20 turns before the width was right.
Here is the video I watched