Ms. Pac-Man 96-1 Issue

RedWarrior80

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I have Mike Doyle's 96-1 kit installed on my Ms PAc. Last night had some people over and right after level 1 on Ms Pac the game gliched and now all we see is 3 Screens of the title screen that appear garbled??? It lets you select games but when you hit start it just reverts you back to the title screen......any thoughts?? Thank in advance.

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It's a PCB issue. It means that pin 5 on the chip at location 3N on the PCB is getting more than 5 volts and is not grounded causing it to display 3 screens. If you look closely at the PCB you'll see rows and columns labelled 1, 2, 3, 4, etc. as well as A, B, C, and so on.
 
It's a PCB issue. It means that pin 5 on the chip at location 3N on the PCB is getting more than 5 volts and is not grounded causing it to display 3 screens. If you look closely at the PCB you'll see rows and columns labelled 1, 2, 3, 4, etc. as well as A, B, C, and so on.

Oh boy I was afraid of this....so what is the usually fix.
 
Luckily, it's a Pac board... probably the most well-documented arcade board in existence. If you need it back by the Holidays, it shouldn't be an issue. There are several people on here that repair boards, and some of them "specialize" in Pacs. You could probably work something out with them if you're not comfortable replacing the chip yourself.

With something like that that seems like it would be an easy fix, they could probably get it in one day, and have it back in the mail to you the next.

As far as what 3N p5 high means, it just means that the IC at the location 3N of the board (a 74LS74 chip) has pin 5 stuck high.

Pretty easy to replace if that's indeed the issue (easily checked with a logic probe). To avoid doing any hard desoldering, it's just a matter of cutting off all the legs of the chip, heating and removing them 1 by 1 (easier than it sounds), clearing the holes, putting in a socket, and slapping a new 74LS74 in there. ... again, that's if that's the actual problem. A quick peek with the logic probe would confirm what is or isn't wrong with that chip.
 
It's a PCB issue. It means that pin 5 on the chip at location 3N on the PCB is getting more than 5 volts and is not grounded causing it to display 3 screens. If you look closely at the PCB you'll see rows and columns labelled 1, 2, 3, 4, etc. as well as A, B, C, and so on.

Replaced the chip and She lives to chomp another Day !!!!

Thanks all
 
Luckily, it's a Pac board... probably the most well-documented arcade board in existence. If you need it back by the Holidays, it shouldn't be an issue. There are several people on here that repair boards, and some of them "specialize" in Pacs. You could probably work something out with them if you're not comfortable replacing the chip yourself.

With something like that that seems like it would be an easy fix, they could probably get it in one day, and have it back in the mail to you the next.

As far as what 3N p5 high means, it just means that the IC at the location 3N of the board (a 74LS74 chip) has pin 5 stuck high.

Pretty easy to replace if that's indeed the issue (easily checked with a logic probe). To avoid doing any hard desoldering, it's just a matter of cutting off all the legs of the chip, heating and removing them 1 by 1 (easier than it sounds), clearing the holes, putting in a socket, and slapping a new 74LS74 in there. ... again, that's if that's the actual problem. A quick peek with the logic probe would confirm what is or isn't wrong with that chip.


Wow that was pretty cool of you man, you took some time to help him out! Pretty awesome! Someone needs to get you a beer!
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