galaga seeing double

finch10101

New member
Joined
Feb 16, 2009
Messages
37
Reaction score
0
Location
Maryland
I just picked up this galaga today for 60 bucks at a yard sale.
Very excited.

At first nothing powered on...they had misplaced a wire.
Then it got to occasional ram errors then freeze, sometimes RAM OK...freeze.

I took the boards out and pulled cleaned and replaced all on the rom board and most on the ram board. Some on the ram board had been "fixed" with leg extensions and I didnt want to touch them as it seemed that it was passing the ram test most of the time.

Anyway now it plays! kinda..

Except the screen looks like this...
Its sort of doubling itself along unseen vertical columns. At the start of the game you have what looks like 2 ships but its not really.
oh and btw i have 5.2 on the board

Any ideas on my next move(s)?
 

Attachments

  • gal1.jpg
    gal1.jpg
    17.2 KB · Views: 34
  • gal2.jpg
    gal2.jpg
    29.6 KB · Views: 27
  • gal3.jpg
    gal3.jpg
    11.1 KB · Views: 35
pulled the video board and realized that some of the previously fixed pins on it had come unsoldered so i cleaned fluxed and resoldered them and im pretty close to sure they're all set. the chip in 4m was actually missing one pin.

my picture is worse now though as seen in picture.
it flies from on side of the screen to the other but you can tell the game is functioning in the background perfectly


where should i start?
should i reflow everything?
i heard brown sockets should be replaced but mine look black.
any ideas appreciated
 
forgot pic on last
also included a shot of a board i have no idea what it does beside plug between the edge connector and harness, whats it do?
 

Attachments

  • gal4.jpg
    gal4.jpg
    36.5 KB · Views: 24
  • gal5.jpg
    gal5.jpg
    37.2 KB · Views: 22
ok im a nub by 00xx do you mean the ic at IL? its labeled 0043?

been tinkering with this all day, just found a phyically damaged capacitor on the video board..C9 which is a .01 mf if i read the schematic right. I bent it up slightly(it was smashed flat) and saw the one lead was cracked off the cap

would this cap cause my flying picture? it cant be good.

thanks
 
Start by throwing away that extra board and plug the edge connector directly into the game board. That wasn't a joke - it really doesn't do anything.
 
What they mean to say about that board, is it's the EMI filter board. It's supposed to reduced electronic interference, but generally the oxidized connectors just cause problems.

As for your cap, it's not critical that it's missing. They use those to reduce ripple going to the TTL chips. Alot of boards will have one for each +5 line going to rows of TTL chips, or they will have one for every TTL Chip, so missing one isn't going to cause the problems you are seeing.
 
well its not the horizontal hold.
im pretty sure its something that i have touched because the first couple times i pulled the boards the screen wasnt going crazy so its something i made worse.

whats weird is that the screen almost looked normal when there were a coulple legs missing on the 05xx and a few unsoldered on the 07xx

whats my next step?
is there a way to tell if the sockets are hosed?
 
well its not the horizontal hold.
im pretty sure its something that i have touched because the first couple times i pulled the boards the screen wasnt going crazy so its something i made worse.

whats weird is that the screen almost looked normal when there were a coulple legs missing on the 05xx and a few unsoldered on the 07xx

whats my next step?
is there a way to tell if the sockets are hosed?
 
well its not the horizontal hold.

If you adjust the horizontal hold, does it get better/worse, but never lock? I'm asking because it looks like your monitor isn't locking to the horizontal sync, and if you can adjust it, but can't get it to lock, then look at the sync circuit. If it's locked to a screen that looks like an out of sync monitor, then I have no idea.

DogP
 
whats weird is that the screen almost looked normal when there were a coulple legs missing on the 05xx and a few unsoldered on the 07xx
05xx won't hurt anything -- it just does the starfield.
07xx also could have been the split problem, and could definitely be the sync problem.

is there a way to tell if the sockets are hosed?
If they haven't been replaced, consider them hosed.
 
when i adjust the horizontal hold i can get it to a point where the letters and ship and stuff dont just look like garble, but they are still flying across the screen super fast and in a changing diagonal manner. So fast its like looking at a cieling fan on high and trying to single out one blade and follow it. I have a feeling adjusting the the hold just kindof tunes the garble from the boards and the monitor into something semi viewable.

So i guess my next move is looking for some boards on ebay i guess
Also where do you get the sockets, might try that first.

thanks for the help
 
ask channelmanic for his galaga renew kit, it cures a lot of problems by just replacing the sipp resistors and sockets.
 
Last edited:
Back
Top Bottom