Baby Pacman gameplay problem.

MC35

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I think I already know the answer but could use a little more guidance. When Playing Baby Pac, whenever baby pac gets eaten by a ghost, the game freezes, other than cherry's dance across the screen non stop. Nothing else happens. I have to turn it off to reset. This is a friends game that I am helping with, so in order to try out suggesstions It will be a little bit in between replys. Suggestions? All the LEDS flash appropriately on both boards.
 
I would start at the vidiot board. If it happens at the same time consistently its probably an eprom issue or its socket. Eproms U9-12.
I have a rebuilt vidiot board for sale if your interested.
 
I will try resetting the eproms and see where that gets me then I'll get back to you. Thanks for the tip. I won't get to this until around Tuesday though.
Mc
 
reseated the ROMS and the processor. Still have cherries dancing across the screen when baby pac gets eaten. Thoughts?
 
Did the mpu have acid damage? Alot of times it runs down on the vidiot board and damages the sockets. Sometimes its not visible until you remove the sockets. Check for continuity on the roms legs to the back side of the board. The same thing goes for the rof of ram chips. Focus on the roms first since they are at the top and get damaged first.
I have the vidiot for sale here. http://forums.arcade-museum.com/showthread.php?t=257893
 
Not so much acid damage as there is corrosion on some of the MPU connectors. The MPU connector kit is on order. The roms looked good, I didn't do the continuity check from the front of the sockets to the back side, so that is something else I can do, right now I'm just waiting on the connectors to come in for J2 and J3 of the MPU. I will follow up once that's done.
Thanks again for your help.
 
Run the communication test and see what it reports.
I repaired a vidiot once that was doing something similar. It would bounce the cherrys across the screen when you tried to switch to the pinball. The problem was rom sockets on the vidiot.
 
Run the communication test and see what it reports.
I repaired a vidiot once that was doing something similar. It would bounce the cherrys across the screen when you tried to switch to the pinball. The problem was rom sockets on the vidiot.

I realize it has been a while since my last post. I was out of town for a bit. I tested all the IC sockets, and I mean all of them. They all check out. I did find that R1 was completely open and R20 was reading higher than the tolerance allows. That could potentially be the problem, but I don't quite understand how those 2 function. I can trace them to the MPU and I0 on the playfield switches, but it doesn't quite make sense to me yet. I will be plugging this back in tonight and looking at the results. I hope replacing the 2 resistors fixes this. If it does, I'm not sure why, but I won't argue.
any thoughts?
 
So replacing R1 and R20 on the vidiot fixed the previous problem of the game essentially locking up whenever baby pac was eat'en by the ghosts. We can finally clear the board and get to the second level...
The newest problem appears to be a ROM problem that doesn't address, or sequence video data but I could use a little help if anyone has ever seen this before. I attached a picture of what the game does on occassion. After resetting power a few times the game comes back to life and we can play it. Any insight on what I should be checking would be great.
Thanks,
 

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The QC on the entire game was so bad, its amazing any of them made it out the door without a failure.

I found on mine, once I got through replacing all the board interconnects and caps, a few sockets, etc. that the leads of the resistors on the videot board had actually delaminated from the lead plating! It wasnt enough to resolder the joint, I had to actally shed the plating layer to get at the the real lead of the component.

It made for some very frustrating intermittent errors.

If your video is going bad, as in random garbage on the screen, start looking at power, and a very hot running video controller chip (ANLxxxxx) and their associated sockets.
 
The QC on the entire game was so bad, its amazing any of them made it out the door without a failure.

I found on mine, once I got through replacing all the board interconnects and caps, a few sockets, etc. that the leads of the resistors on the videot board had actually delaminated from the lead plating! It wasnt enough to resolder the joint, I had to actally shed the plating layer to get at the the real lead of the component.

It made for some very frustrating intermittent errors.

If your video is going bad, as in random garbage on the screen, start looking at power, and a very hot running video controller chip (ANLxxxxx) and their associated sockets.

It's funny you mention the delamination, when I was replacing the 2 resistors the pads on top of the board came off with the resistors and I'm fairly confident in my soldering skills.
As far as sockets, they are all good. I looked into IC's running hot and found a repair site that mentions that very same problematic issue with this board. I will be ordering some heat sinks and the color adjustment pots. Slowly but surley I will get this game working again. But I am experiencing your frustration.

Thanks for the input, it really helps confirm what I have been discovering.
 
It's funny you mention the delamination, when I was replacing the 2 resistors the pads on top of the board came off with the resistors and I'm fairly confident in my soldering skills.
As far as sockets, they are all good. I looked into IC's running hot and found a repair site that mentions that very same problematic issue with this board. I will be ordering some heat sinks and the color adjustment pots. Slowly but surley I will get this game working again. But I am experiencing your frustration.

Thanks for the input, it really helps confirm what I have been discovering.

I have a pot set for the vidiot board on my website.
http://www.twistywristarcade.com/kits/970-baby-pac-vidiot-pcb-potentiometer-kit.html

Yes it is common on these boards to have a dirty copper pad after a part is removed. Its like the solder never flowed to the pad on the top side. The problem does not seem to be on the bottom side so as long as the through hole plating is intact it shouldnt cause any problems.
 
It's funny you mention the delamination, when I was replacing the 2 resistors the pads on top of the board came off with the resistors and I'm fairly confident in my soldering skills.
As far as sockets, they are all good. I looked into IC's running hot and found a repair site that mentions that very same problematic issue with this board. I will be ordering some heat sinks and the color adjustment pots. Slowly but surley I will get this game working again. But I am experiencing your frustration.

Thanks for the input, it really helps confirm what I have been discovering.


I never found a reference on how to adjust those color pots on the videot, so I came up with my own method that results in a really clean RGB signal: http://coinoplove.com
 
I have a pot set for the vidiot board on my website.
http://www.twistywristarcade.com/kits/970-baby-pac-vidiot-pcb-potentiometer-kit.html

Yes it is common on these boards to have a dirty copper pad after a part is removed. Its like the solder never flowed to the pad on the top side. The problem does not seem to be on the bottom side so as long as the through hole plating is intact it shouldnt cause any problems.

I just ordered these from BOB Roberts. I just hope I ordered the right footprint. I didn't have the board in front of me when I ordered. Like I said this is for a buddy. If they are the wrong size I will order the set from you.
Thanks,
MC
 
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