Galaga rebooting over and over? Video attached.

[Tate10]

Wondering if anyone has any advice on where to start.  The game just keeps cycling the start sequence over and over.  Thanks Tate

http://youtu.be/qNLU3gICLnU

[iankellogg]

It looks like it is having some ram issues. I could be wrong but the fact that the test pattern is messed up is a sign of something wrong with the PCB most likely in the RAM->video stuff.

[lesoleil70]

check the roms maybe , just like the pacman video john did.  Might have been the gyruss.
the one where he compared the files to a trusted rom download source.


pulled this from arcadeotaku

Symptom: Reboots constantly
This is different than the bad CPU socket problem in that it wasn't stuck at RAM OK but rather as soon as the crosshatch then the text came on the screen it rebooted. The Reset line on CPU #2 and 3 came active for a VERY short period of time then the game reset.
Swapped out the CPU sockets. Subbed out the custom chips. Nothing. On a whim I turned off each DIP switch and found by playing with them that when DIP switch #3 at 6J was on it would cause the system to lock up when running or to constantly reset when booting.
Replaced the 74LS151 at 4K and the 74LS368 at 5A. Problem still there. Checked the EPROMs again. They were all checking good on the programmer. Swapped out the first 2 program EPROMs. Nothing. On a whim I burned a new set of Williams EPROMs (these were Namco) and swapped out all the EPROM.
Problem fixed.


plenty plenty more here - dip switches etc etc
http://wiki.arcadeotaku.com/w/Galaga_Repair_Logs

[iankellogg]

WOrth a shot but the cross hatch being fucked up is not a good sign.

[atariforever2002]

My non-professional guess, you got voltage issues on the ram side of things. Had a buddy's do something similar. Had to send it to someone with a logic prob.

[iankellogg]

Actually that is a really good point I forgot to mention. Double check your edge connector and power supply if the voltage gets a bit low it can cause lots of issues.

[Tate10]

Thanks for the help.  I will start with the power supply and voltages and go from there.

[ousoonerfan2006]

Dirty ram/roms, black tarnish accumulates on the legs of the chips and causes a lot of issues with mine, buy a can of tuner cleaner from RadioShack and remove the chips one by one and clean them.

[Tate10]

ousoonerfan2006 that's exactly what I did and you are right the majority of the chips had a lot of black tarnish.  It works great now except in freeplay.  If I set the dip switch to freeplay it goes through a boot cycle and just keep cycling.  Switch it back to coin and it works with no problems.  Any ideas on that?  Not a huge I don't mind opening up the coin door and adding credits.

Thanks
Tate

[ousoonerfan2006]

I haven't messed around much with free play on mine, I just put a credit switch behind the reject button on the coin door. I'm glad it worked out for you. I will try putting mine on free play and see what happens, sometimes you have to have certain switches on or off for free play to work or it goes into a boot cycle.