John's Arcade Forum - Classic Arcade and Pinball Collecting and Restoring Discussion Forum - RETRO MAME - Nintendo Vs Forum

Hi, everyone...my name is David and I just several months ago acquired a Centipede cabaret model from a mechanic's shop that just had it sitting in a corner. It was working fine and then one night while I was sleeping, I awoke to the most awful screeching noise. I went into the room where my game is located only to find that the screen looks like it's going haywire and the constant noise I was hearing was coming from the speakers. I'm definitely a novice when it comes to these games, but I'm guessing that this is some sort of power issue. It's been unplugged since that night and I've periodically gone back to plug it in and check it out, each time resulting in the same issue. Does anyone have any tips for troubleshooting this? Was there a common issue with these that may be causing the problem I'm having. I do have a multimeter so I can test whatever needs testing. Any help figuring out the root of this problem would be greatly appreciated.

Have some one check your flyback, when they crack they will make the noises  you are hearing, and cause electrical  proublem  you are having. Best to leave the game off until uou have it looked at... 1 thing you can do is make sure the neck board is connected firmly.  If it has pulled off you will get arking between the pins.and it will cause a high pitched sound also.

Charles,

Thank you very much for taking the time to reply, I'll do as you suggested. However, the sound is definitely coming from the speaker...I can put my ear up to it and hear it. Do you think what you're saying may still hold true? Thanks again.

R/S,

David C.

The arking will cause issues with your sound and video, the arking will cause voltage issues on the chassis, and interference wich will be picked up and amplified  by the audio circuitry and the sound will be heard  in the speakers

Thanks for the explanation. I found some information online for troubleshooting this. I'll be giving it a try within the next few days and will let you know. Again, very much appreciate your time.

David

Try to take a picture of the messed up screen and post back and someone will probably be able to tell you if its your game board or a monitor issue. My Centipede is a game board issue it looks like this and a squeal is coming out of the speakers as well.

(http://imgur.com/1uGBpJh.jpg)

Ok, this is slightly different, you have a balnk area on the screen, and it looks like the boot up screen. So i would guess information is not being sent out, so you have a bad chip on the board, and the board is watch doging, it,s trying to start but it can,tbecause of a error.

Yeah i have some bad ram and a bad rom as well. Maybe more. one problem at a time.

Before you go crazy, did you check voltages? Start simple and work backwards. Improper voltages will cause issues like this.

Voltages are good, I ran the roms through my programmer and one was corrupt. I tried to erase it but it would not erase completely. Just waitin on some used roms from fleabay and a couple 2114 ram moduals. I did get it to partially work by piggybacking some ram I borrowed from a working ms pac board. I was able to coin up and play but the archer was missing.

I got a bit further on my Centipede. Swapped ram, burned one rom, cleaned socketed IC legs.

(http://i.imgur.com/2lYTAaz.jpg)

No moving sprites yet but saw a post about 74ls163 at 5A and 5B fail regularly. I am able to coin up, start a game and fire and move the invisible archer.