sega rally 2

[duncthepunk]

Hello everyone . I would like some advise about sega model3 step 2 boards .i am working on a 2 player machine and one set of boards is playing up ? the image is tearing ? going single colour ? . I don't know a lot about these boards ,But i been told that they are a pain to work on because they are stacked on each other . Is it possible to run 1 board set without the other ? (they communicate to each other) . i checked the power to both boards and the game is up and running on both. but after a few minutes the graphiics starts to do strange things ripping and not rendering ? . swapped over the boards and the problem jumped to other side . I thuoght it could be capacitor issues because of the age . But have been told they rarly go wrong ?Would it be a good idea to pull out the roms and clean the legs and sockets ? . Like i said i do not know enough about these boards . so caution is always the best way forward. ( i mainly do pinballs). any advise would be most welcome > yours dunc

 

[Kev A]

Yeah its possible to run both games as standalone, you need to go into the menu and change both to single from twin.
Before you go pulling any chips have you checked the fans in the cage are spinning and nice and clean and adjusted the voltage (carefully) so you are getting a solid 5v at the board level.

 

[Sbdesign]

The board has a cpu, video & game Rom board per side.
As Kev says, each stack can run on its own.

It sounds like you’ve confused a bit of info.
I think it’s the fact you need the 3 boards in 1 stack all together to test working is the difficulty, and not because side right and left are linked through optical fibre

 

[duncthepunk]

hello again the boards were tested in metal cab . to see if the propblem was on the one set of boards i removed both metal cabs and swapped them over and the problem moved onto the other side . so the problem is with one of the boards ( i suspect its the either graphic or the cpu board ) but more likely to be graphic board because the game is running the other board set ran ok on the other side so it should't be a power issue (we hope) . will get back to this some time in the next couple of weeks and try to upload a video of the problem . if the cpu had a issue it would stop running code ? it might be the metal cage ? will swap graphic board onto the other set and see if it fails .

 

[Sbdesign]

Now swap boards on the stacks to find out which board.

Tip:
Write A1,A2,A3 on the three boards of one stack and repeat with prefix B on board too

Then write down the combos so you can tick off or comment what happened

A1 B2 B3 = no fault
Etc
Etc

We all been there loosing track of what we done and haven’t half way through

 

[Redleader1]

Sounds like video board, if you need a repair let me know !