Problem Namco Galaga '88
- Thread starter AlexK
- Start date
GadgetFreak
Active member
Common failure on those is the 6809 cpu's, it has several. Also the customs are another failure point and there are quite a few on the smaller board.
Lastly a lot of the boards I have seen have a lot of corrosion on the rom boards.
But if you have 2 at least you stand a good chance of getting one working fully.
Lastly a lot of the boards I have seen have a lot of corrosion on the rom boards.
But if you have 2 at least you stand a good chance of getting one working fully.
Retroman839
Senior Member
Transistors in the video circuit
I had where bad
I had where bad
Funhouse71
Active member
Also check D1 diode near the edge connector if this goes open circuit this can also cause a dead board (black screen)
DonkeyKongler
Newbie
sorry,
but you are wrong with this.
this is a over voltage protection diode (zener) and it is open normally.
If the voltage rises above 6.2 volts, it short circuit the power suply permanently and protects the PCB......
Funhouse71
Active member
I make you correct, I must admit when I posted this yesterday I couldn't remember whether this was open circuit or shorted on my board causing a dead board so must of been shorted like you said, it was many years ago now but was the fix for my board and something Alex should be checking on his board.
Retroman839
Senior Member
Even with blank screen
Try coining up and turning volume up ,,
My blast off only had a very weak blue video signal left to show a very faint blue image .. if it was a nice day in a well lit room no image was visable
Always hit coin up to see if
It’s playing but no image you will still have sound
At least then you know cpu partially working..
Trouble with these is no image can be bad cpu as well ..
Try coining up and turning volume up ,,
My blast off only had a very weak blue video signal left to show a very faint blue image .. if it was a nice day in a well lit room no image was visable
Always hit coin up to see if
It’s playing but no image you will still have sound
At least then you know cpu partially working..
Trouble with these is no image can be bad cpu as well ..