Frogger board problem

SaminVA

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Now that I got my Pacman working it's got me in the mood to get some of my projects games running. I bought a dedicated Frogger back in 2005 off Ebay because it was local to me. I only paid $188.05 for the game and it was in pretty good condition but it had a monitor sync problem. It's been out in my garage all this time and I used it to test parts of my Pacman monitor as they are both K4600's. Before I pulled the monitor out of the cabinet after moving the game so I could get to the back easer I noticed the game had developed a problem with the graphics. Now the monitor is rebuilt and ready to be installed but now I have to figure out what's wrong with the board. I removed the board and brought it inside the game room to work on. I had bought a Konami 36 pin to JAMMA adaptor years ago for a Gyruss board so I figured I could use that on my JAMMA cabinet. I hooked it up and got the same problem it had in the Frogger cabinet. I removed all the ROM chips, pins and sockets looked good and clean but the Z80 CPU had rotten legs. Two legs broke off and was left in the socket. I picked them out and put a new Z80A in the socket and fired the game back up and I still had the same problem. I posted a video on YouTube and also here are a few pictures. I am hoping someone has seen this problem before and can point me in the right direction. Looks like it time to get the logic probe back out.
Thanks for looking.

 

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I don't know if these symptoms are typical of a Z80 issue or not, but if your legs were corroded and broke off, it's possible the socket itself is bad. Maybe try wiggling the chip in the socket to see if there's any change. I'd probably replace the socket anyway just to be safe.
 
I don't know if these symptoms are typical of a Z80 issue or not, but if your legs were corroded and broke off, it's possible the socket itself is bad. Maybe try wiggling the chip in the socket to see if there's any change. I'd probably replace the socket anyway just to be safe.

Thanks, sounds like good advice. So far I took a logic probe and poked around a little. I found what I call a sour note on IC-18 which is next to the ROMs. It's a 74LS138 and I looked it up in the manual and it's listed in the Video Fault under Picture Mosaic so it might be bad but first I decided to remove all the ROMs and check them with my Pocket Programmer and see if they read good. If they are good then it's time to replace sockets for the ROMs and CPU as well as replacing IC-18. I got plenty of 74LS138s :)
 
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