Galaga Booting freezes at Ram OK

toyzngames1

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Picked up this game and it was playing but would reboot during game play. So, I put in new fuse holders, new main connector, set power supply at 5.1, re-capped he monitor and did some major cabinet repair. I put it all back together and it starts to boot but stops at the upside down, Ram OK. I pulled the board out, lifted and reseated all rom's and z-80's and the ribbon connector more than once but it still freezes up. The board was rebuilt by Eldorado in 2005. Help!!!
 
Since the game was rebuilt; new sockets and resistor packs, The next step in the program is to start the other z80 processors so that is where I would look. When the game boots up The other processors just sit there while the ram rom test is done by the first cpu.

It is kind of cool to watch all of that activity suddenly spring to life on the cpus on boot but that is not what your board is doing.

Try replacing/swaping the cpus and see if the problem changes. The first cpu is supposed to be an z80a but I have boards that have a regular cpu z80 in that location from factory. I try to buy the z80a chips and sometimes you can find the z80b chips cheaper in a lotl.

The upside down part is right before the other z80's start if it is not a cpu it is probably a custom. Check the 07xx clock chip as they seem to go bad first, most all of the pins should have some activity.
 
Eldorado doesn't necessarily replace the sockets or resistor packs. Check those for the old style and replace them if they are still there.
 
Eldorado doesn't necessarily replace the sockets or resistor packs. Check those for the old style and replace them if they are still there.

If this is the case; You need to get a re new kit and replace the parts with the ones supplied with the kit. Most times if you have the flat resistor packs you have them crappy sockets also.

In any case you really need to look at them sockets and maybe post a pic of the customs in the sockets as well as the z80s.

I would try new z80(a,b)first but I keep several on hand just for that reason.
 
still working on it.

Sorry for the delay. The board has the 5 volts at he board. What can I safely raise the voltage to without killing the board, to see if it will boot at a slightly higher voltage. switched the z-80's from one to the other. I also checked the dip switches at 6j and they are off at 5 and 7. Still stuck at ram ok. Where can I get this renew kit?? I will attach a couple pictures. Thanks for any and all help.
 

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Sorry for the delay. The board has the 5 volts at he board. What can I safely raise the voltage to without killing the board, to see if it will boot at a slightly higher voltage. switched the z-80's from one to the other. I also checked the dip switches at 6j and they are off at 5 and 7. Still stuck at ram ok. Where can I get this renew kit?? I will attach a couple pictures. Thanks for any and all help.

http://www.arcadecomponents.com/modkits.html - Instructions are in the download section.

Anything that causes CPU2 or CPU3 to halt can cause the problem you are seeing.

RJ
 
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