My Pac Man has died

[benkeezer]

Maybe this will help:

http://lawnmowerman.rotheblog.com/

I used it to repair my Pac Man. Good luck.

 

[AtHomeTech]

Are dips 7 and 8 set correctly or are they set to 'freeze'?

 

[Torin]

Are dips 7 and 8 set correctly or are they set to 'freeze'?

They are both set to the off position. I double checked that with troubleshooting steps from the Lawnmowerman pages.

I have also checked all the voltages from the lawnmowerman pages on the diodes D7 and D8, D3 and D4. The voltage all meet the minimum indicated and might even be running a bit higher than the indicated normals.

At this point, unless there are other suggestions, it seems like I might start by switching out the Z80 and other roms with my other good board.

Unless there are any other ideas.

Thanks for your help.

 

[Dokert]

Touch base with Riptor, he is very good at these boards.

I am probably wrong, but I am thinking VRAM or Sync Bus daughter board issue. Have you tried reseating them?

 

[SuperGunGuru]

Touch base with Riptor, he is very good at these boards.

I am probably wrong, but I am thinking VRAM or Sync Bus daughter board issue. Have you tried reseating them?

Agreed. My Ms Pac has a crappy socket for the VRAM board and I've had to re-seat it occasionally to get the board to boot.

 

[postmortem01]

My Ms. Pac died but I was able to bring her back. The problem ended up being the ribbon cable and the harness connector.

 

[Torin]

Touch base with Riptor, he is very good at these boards.

I am probably wrong, but I am thinking VRAM or Sync Bus daughter board issue. Have you tried reseating them?

I was also thinking VRAM from what I have read. I also read this on the Lawnmowerman pac man page and this is located on the VRAM board:

"Plays, Screen Full of "F"'s on power-up. Intro screen full of red "1"'s.

74LS257 at U3 pin 3 out of circuit."

I've reseated the VRAM board but will try again or try to boot it up with the VRAM board from my working pac board to try to narrow it down. I'll post the results here and try to contact Riptor if it doesn't work. Thanks again.

 

[Torin]

I was also thinking VRAM from what I have read. I also read this on the Lawnmowerman pac man page and this is located on the VRAM board:

"Plays, Screen Full of "F"'s on power-up. Intro screen full of red "1"'s.

74LS257 at U3 pin 3 out of circuit."

I've reseated the VRAM board but will try again or try to boot it up with the VRAM board from my working pac board to try to narrow it down. I'll post the results here and try to contact Riptor if it doesn't work. Thanks again.

Ok, I replaced the VRAM board and I now have pac man!

The bad new is that I have very distorted sound and loud humming and I have two or three huge white bars that scroll vertically across the screen. I have read about the hum bar and was wondering if it is the same. I will get pics up soon. Any ideas on the white lines and sound issues while my camera battery charges?

Test mode indicates memory ok. I can get the humming sound to increase by touching the diodes in the sound area of the board.
D7 and D8 still very hot to the touch.

Getting there!

 

[Dokert]

You may need to do a cap kit on the board. Bob has them, or Riptor may have them too.

 

[Torin]

You may need to do a cap kit on the board. Bob has them, or Riptor may have them too.

I'll have to do that.

I think its something with an audio component. Something is shorting out and the loud hum has just blown both of the 5 Amp fuses.