Riptor
Well-known member
Shall I bring you a trade in board to Crabtowne?
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Please post all monitor technical topics in the Technical - Videogames - Monitors section, not in the General Help section.
Ms Pac giving me a blue sac (help needed)
- Thread starter vintagegamer
- Start date
OP
OP
Looks like I won't need that, but I might need something else from you
Here are some updated findings as of tonight (now that I know how in the hell to check power across a cap):
1. cap at C3 is reading 5V
2. cap at C2 is reading 5V
3. 2 big caps above C3 are reading 7.2-7.3 each
4. the big 25V cap up by the edge connector is reading 15.8V
5. the little cap to the right of the one in #4 is reading 7.8V
After doing some further reading out on KLOV as well as the interwebs, I have a strong suspicion the problem lies with the little board at 6D. One of the small chips on the board has brown around all of the solder on the back side. If you're looking at the little board while it's installed on the main PCB, it would be the little chip in the upper right corner that appears to be fried.
That being said, it looks like I am in need of a replacement of that little board that plugs into 6D to make my demons go away. Can anyone (Riptor or otherwise) help who might have an extra working one for sale? I can send the one I have as a core if needed.
note: as much as I've gone through with this machine, I once again have learned a TON on how to work on these machines. It has really been all worthwhile!
Riptor
Well-known member
I have replacment sync bus cards in stock. Save your old one, if its bad it can be repaired. FYI, TTL chips dont usually burn up in a literal sense. Are you sure thats not just a stain from something getting spilled on it such as soda or mouse piss?
OP
OP
Its only on one of the chips, so the mouse must have really good aim!
Riptor
Well-known member
Post a picture
OP
OP
You got it, will do tonight.
Peale
Active member
Sounds like solder flux. If it's been worked on before there's a darn good possibility there would be flux on it.
Examine both boards carefully, make sure there aren't any broken solder joints or bent pins. Also, the sockets on the board suck, they may need replacing.
Examine both boards carefully, make sure there aren't any broken solder joints or bent pins. Also, the sockets on the board suck, they may need replacing.
DaveyPocket
Member
I've seen this on several boards. Usually that brown stuff is residue from certain types of solder. If that is the only chip that has that stuff on it, it means that the chip you are talking about was replaced by someone (a long time ago).
But yes, I picture will help.
OP
OP
Well I was all set to post the pic last night, and on the way home I got a surprise update that I was babysitting my niece along with my own 2 kids. So, no pic upload yet. It's coming though.
OP
OP
DaveyPocket
Member
That brown residue under the chip seems to be normal, it shouldn't affect how the chip operates. Though that replacement chip that was installed there could be dead, again. Though earlier in this post you said you kept getting RAM error messages. Are the RAM chips removable? Also, is the garbage on the screen moving/flickering or is it stable?
OP
OP
The RAM chip errors appeared briefly in the beginning and then I never got them anymore. Sometimes the garbage is static and non-moving, other times you see a couple of the garbage characters moving as if something is going to happen, but it never does.
OP
OP
In another post, someone recommended squeezing the edge connector to see if there is a connection issue between the connector and the board. I haven't tried that yet but wondered if that's still a concern if I'm getting the voltages I posted in this thread?
DaveyPocket
Member
I'm not sure if the edge connector is causing this sort of problem. Though what you can do is clean the contacts on the connector and the board. Also, make sure some of the contacts on the board aren't burnt or corroded (happened on my Pacman board). Also, you said you removed and reseated the chips (ones that were in a socket). Does it look like any of the pins on the chips are black or oxidized? They should be silver/shiny. If they are, remove the chips and clean them.
I'm just going through some troubleshooting things that might fix this issue. Another thing, make sure the ROM's are put in their correct sockets (another problem with my Pacman).
If you received a RAM error earlier, it might be RAM.
Try some of these things, see what happens.
One last thing. If you have another Pac/Ms. Pac machine. Try passing components between the two boards one at a time (Power up the working board with the Processor from the non-working board, see what happens, do this with ROM's, RAM's, expansion boards, etc..)
I'm just going through some troubleshooting things that might fix this issue. Another thing, make sure the ROM's are put in their correct sockets (another problem with my Pacman).
If you received a RAM error earlier, it might be RAM.
Try some of these things, see what happens.
One last thing. If you have another Pac/Ms. Pac machine. Try passing components between the two boards one at a time (Power up the working board with the Processor from the non-working board, see what happens, do this with ROM's, RAM's, expansion boards, etc..)
OP
OP
I've thought about this one, but my other one is a Coney Island special, and has been rigged up worse than a mobile home in Memphis (not by me, by the prior owners). I'm afraid that if I start swapping components, I may have 2 Ms Pac's needing a gyno..
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Riptor
Well-known member
The offer is open if you want to bring the board down one day. I will give you a crash course on repairing the pac board.
OP
OP
Greatly appreciated but you're 3 hrs away from me
These days just getting to the Home Depot up the road and back seems like it should get a touchdown dance!
