I have a strange Final Fight problem, help please! (UPDATE: C board issue??)

Check the kit manual here:

https://www.arcade-museum.com/manuals-videogames/F/final-fight.pdf

 

Look for the smoke test, Read for possible information (aka 74ls04 sync problem)

 

Failing that, You could have a board fault.

Thank you for that.

 

The thing I am stumped by is that the synch fault I have is not listed. Plus, I have tried different A and C boards (both FFs are all original, including C board). I bought Carrier Airwing off the same seller which was supposed to be 100% working, which was a lie. The A board was faulty and has corrupted graphics. Using the faulty A board even has the same fault with the FF B+C boards. Albeit with corrupt graphics. I have not been able to find a write up or advice on this particular fault at all.

Thank you for that.

 

The thing I am stumped by is that the synch fault I have is not listed. Plus, I have tried different A and C boards (both FFs are all original, including C board). I bought Carrier Airwing off the same seller which was supposed to be 100% working, which was a lie. The A board was faulty and has corrupted graphics. Using the faulty A board even has the same fault with the FF B+C boards. Albeit with corrupt graphics. I have not been able to find a write up or advice on this particular fault at all.

 

Might be some helpful info in this thread

https://www.aussiearcade.com/showthread.php/80276-Capcom-CPS1-quot-C-quot-Board-Repair-(Pic-Heavy)

Well looks like my original post was wrong. It IS the C board. I swapped them again and the fault happened on the Jp board.

 

Probably talking to myself here, but I am wondering if it could be one of the little transistors (???) at the bottom of the board underneath the B-04 chip. The small socketed chip on the B board underneath the C board could be the chip that controls the resolution? This is why I am thinking it could be the little resister thingies because they connect to the chips under the C board. Pretty sure anyway, only had a quick look.

Edited October 15, 2018 by Segasonic91

Well looks like my original post was wrong. It IS the C board. I swapped them again and the fault happened on the Jp board.

 

Probably talking to myself here, but I am wobdering if it could be one of the little transistors (???) at the bottom of the board underneath the B-04 chip. The small socketed chip on the B board underneath the C board could be the chip that controls the resolution? This is why I am thinking it could be the little resister thingies because they connect to the chips under the C board. Pretty sure anyway, only had a quick look.

The issue is you have a fault on the A board not b or C..

But I put the C board from the problem board onto the fully working Japanese board and I had the "showing the top half of the screen on the bottom half of the monitor" problem. Surely that means the C board is the at fault??

But I put the C board from the problem board onto the fully working Japanese board and I had the "showing the top half of the screen on the bottom half of the monitor" problem. Surely that means the C board is the at fault??

Have you tested it with another A board ?

Yep, same thing with different A boards. Both original and Dash. Even the faulty glitched graphics A board I got with Carrier Airwing.

have you tried looking for dry joints on the c board ie the surface mount custom chip etc?

Yeah that is what stumped me as well, the B-04 chip looks perfect. The solder joints look shinier than the working board. No PAL chips to clean either which is why I suspected one of those little transistors. I have to check again, but I think the socketed chip on the B underneath the C has something to do with resolution handling, the service manual that ozfalcon was kind enough to link to for me mentions it. The two resistors look like they connect to that chip going by the markings on the B and C boards. I have no clue what to replace them with though.