RESOLVED: Galaga issue

wishiwas

Active member
Joined
Sep 21, 2018
Messages
105
Reaction score
33
Location
New Hampshire
I had my Galaga machine on for a few hours. When I came back in the room the screen was frozen. I powered it off and turned it back on and now only only get this screen.
I removed every socketed chip and cleaned all the pins. Reinstalled the chips, removed and reinstalled the ribbon cable.
I also turned the 5v up on the power supply (I'm running a switching PS) checked the voltage at the input plug.
I realize the sockets in these machines are crap, but it's funny it would croak just leaving it on.
I assume my issue is on the cpu board?
I have 2 Galaga parts boards i can swap chips with.
 

Attachments

  • 483487620_122225051414018513_2833393293199364848_n.jpg
    483487620_122225051414018513_2833393293199364848_n.jpg
    60.6 KB · Views: 19
  • 482126350_122225051444018513_6403530245710890338_n.jpg
    482126350_122225051444018513_6403530245710890338_n.jpg
    282.2 KB · Views: 19
If you have any spare processors, you might try replacing them to see if anything changes. Galaga uses 3 Z80A processors.

Thanks,
Jason
 
If you have any spare processors, you might try replacing them to see if anything changes. Galaga uses 3 Z80A processors.

Thanks,
Jason
Hi there, Yup, plenty of spare cpus from Pac Man boards. Z80a. No change. :( I swapped every chip as a matte of fact one at a time checking each time I swapped as to not shotgun a problem.
 
Will it go into test mode?
Just tried, no. No response at all.
I dont know Galaga boards like I know Pacman boards, so I am unsure of the cap readings.
From what I read on the meter so far, everything looks ok there (famous last words!)
 
Darn. Well, APAR does have a cap kit for Galaga that I've installed on my board. I'm not sure if it would be helpful with your situation. Lots of customs and other chips that could be the problem. Might be one that needs to be sent out for repair.

Jason
 
Swap the 08xx around and check if something changed.
They prone to die.
I took every chip off of 2 other non working boards and swapped chips one at a time. My guess at this point is sockets or another parts like caps have died. I hope its.not sockets.
 
Or you have a non-socketed component that is causing the problem. Personally, I'd try the cap kit. I'd spray DeOxit in the sockets and on the ribbon cable pins. Did you check the pins for the ribbon cable to make sure none are bent/broken? Grab a fiberglass pen or an eraser and clean the edge connector. Spray it and the wiring harness connector with DeOxit.

Thanks,
Jason
 
****** U P D A T E *******
I bought the 7 caps I saw listed in a Galaga cap kit today and just got them installed and I finally get a boot screen, but with an error. I put a replacement 911 ram chip in 3H but I cant get beyond this error. I bought a can of contact cleaner. I will pull the chips later and spray away! 1000000649.jpg
I put a new ram chip in 1000000648.jpg
 
I would bet you have a damaged trace or pad that finally burned up under a socket. The 3H message can be a lot of different things.

Jason
 
Update: problem solved. I must have had the power up too much. I brought the board to work and used a pc desktop power supply and at least got the screen below. This chip is the Galaga enhancement kit so that's why it displayed that message.
Got home plugged it back into my test bench and sure enough I got the junk. Turned down the power to 5 even and it powered up with the same screen below. Installed the kit and fired it up and she is 100% bottom line of this fix was i had a capacitor go bad. Replacing them was the resolution.
 

Attachments

  • 20250313_080901.jpg
    20250313_080901.jpg
    134 KB · Views: 10
  • 20250313_143713.jpg
    20250313_143713.jpg
    257 KB · Views: 10
Last edited:
This is really surprising. I was under the impression that a bad cap wouldn't keep a board from booting. IDK where I got that from.
 
Interesting. Mine is like this and seems stuck in reboot sequence… I was thinking a lot more wrong here than caps too.
 

Attachments

  • IMG_3982.jpeg
    IMG_3982.jpeg
    521.7 KB · Views: 1
Back
Top Bottom