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

hello everyone. I am kind of new to the arcade collecting and repairing and i have a question about an arcade i picked up for free. it is 10 yard fight in a defender cab. now before i did anything i checked online for an irem wiring pinout and found a few but i am not to certain if it is right. If any one has a irem pinout for this game i would really appreciate it. what i have done is eliminated all wiring except monitor hook up and the 12v, +5v, ground and speaker connection. during a few test the monitor will power up without board connected. if i connect the board the monitor has a little flicker like the game is trying to load but flickers every few seconds. Any help is much appreciated. Thanks.

David

The pin out is right on klov.
http://www.arcade-museum.com/pinouts-class/Irem.html


It sounds like it is most likely watchdog resetting. It could be also a monitor sync issue but the flashing sounds more like watch dog resetting.
I am not sure if you will be able to easily check for that.

thanks for the reply. I just fiddled around with it a bit more what i did was disconnect the sound board and i got picture still rolling so i adjusted the h and v sync and got it working fine but for some reason when i connect the sound board back up it stops the game from starting up. i get a black screen with the flashing every few seconds again. any ideas? is there a way to test sound board?

Good job finding that solution!
That is a huge luck out that you can do that. it helps a ton towards fixing this game.

I don't quite feel like diving into the schematic at this time but from what little i did look at before i saw that there is some kind of data/address sharing going on between the sound board and the main cpu board which is the one in the middle. It is likely some chip is shorting out the shared bus. You could probably use a multimeter and some guidance to figure out what chip is bad and then be prepared to solder in a new one.

I have the schematics for this game but the sound board one is blurred and can't read it well where is the sound chip location any identifying marks on it and what test should I do to it?

Well the whole board is kind of the sound chip in a way. There is a sound processor, some eproms, some ram, the sound generator IC, the dac, amplifiers. the whole 10 yards.

What kind of test equipment do you have? Multimeter? Logic probe?

I have a multimeter I was doing a test on one chip and I was reading about 1.5 vdc on all legs except for 2 one on one side and one on the other had no voltage.