liquidx
New member
I have a G05-802 monitor that's driving me mental, maybe someone here can help.
I have a working asteroids game board, it plays fine on the scope (also when getting the signal from P100)
I had problems with the monitor losing horizontal deflection and the spot killer coming on as well as chassis transistors blowing and even though I went through every single component and checked the input voltages (steady 95v coming in to P500 etc) I still couldn't get it to work.
Anyway, I just got a new working/tested deflection PCB as a comparison/reference point, hoping that would help me see what was wrong and, in any case, finally get the game playable.
When I plugged this new PCB in, the spot killer was on and I had no horizontal deflection. I can logically deduce from this that my problem is outside the PCB.
Powering it up a second time to take some readings, the spot killer was still on but I'd lost the picture, turning brightness/contrast up only produced a faint haze towards the top of the screen.
Looking at the PCB, R713 was burnt to a crisp. So I gave it a closer inspection and found Q705 and Q706 to both be shorted. I checked the chassis transistors, they're fine, I looked for shorts in the sockets, plugs and cables leading to them but found nothing wrong either.
Grounds seem to go where they should also.
The vector FAQ talks about a white haze on the screen being linked to HV failure but it was measuring fine before this (including a good 12KV).
As the 3 components that blew are neighbours, I've been trying to trace back from there for a source but I can't figure out the problem (with my limited knowledge anyway).
Any pointers would be much appreciated (by my girlfriend too who's been playing it on the scope
)
Thanks!
Colin
I have a working asteroids game board, it plays fine on the scope (also when getting the signal from P100)
I had problems with the monitor losing horizontal deflection and the spot killer coming on as well as chassis transistors blowing and even though I went through every single component and checked the input voltages (steady 95v coming in to P500 etc) I still couldn't get it to work.
Anyway, I just got a new working/tested deflection PCB as a comparison/reference point, hoping that would help me see what was wrong and, in any case, finally get the game playable.
When I plugged this new PCB in, the spot killer was on and I had no horizontal deflection. I can logically deduce from this that my problem is outside the PCB.
Powering it up a second time to take some readings, the spot killer was still on but I'd lost the picture, turning brightness/contrast up only produced a faint haze towards the top of the screen.
Looking at the PCB, R713 was burnt to a crisp. So I gave it a closer inspection and found Q705 and Q706 to both be shorted. I checked the chassis transistors, they're fine, I looked for shorts in the sockets, plugs and cables leading to them but found nothing wrong either.
Grounds seem to go where they should also.
The vector FAQ talks about a white haze on the screen being linked to HV failure but it was measuring fine before this (including a good 12KV).
As the 3 components that blew are neighbours, I've been trying to trace back from there for a source but I can't figure out the problem (with my limited knowledge anyway).
Any pointers would be much appreciated (by my girlfriend too who's been playing it on the scope
Thanks!
Colin