Problem with K7000 and a white screen

[smac666]

Hi,

I have a problem with the monitor in my defender cabinet.
I had been restoring the cabinet and had the game set up on a bench.
Monitor and games worked fine, I blew everthing down with air and put it back in the cab.
Now when I turn the game on all I get is a white screen, see attached photo.

I think its a senith chassis as it have 2 red anode leads.

If you disconnect all the inputs and power the monitor on then it fires up like normal with a blank screen.
Connect the wires and its all white, I tried a different monitor and the game worked fine.

I pulled out the chassis and reflowed the solder on the back side.

Still get a white screen. anyone got any ideas.

Regards
Steve

[grantspain]

sounds like something is unplugged on the video side of the chassis,either that or you have some kind of blanking problem

[Ken Layton]

Did you accidently unplug/plug something in wrong?

Bump the "SCREEN" control on the flyback?

[smac666]

Hi,

Sorry for the late reply but work has been interfrening with my social life.

I tried to wiggling the focus and screen controls but got nothing new.
I rechecked all the connectons and can't see anything obvious that is wrong.

I have a spare board from a single anode Lead chassis (none zenith I think) K7000 and changed the neck board and chassis out and the monitor came up fine, So its definetely the circuit board that has a problem. 

So what the most likely cuplrit?

Reagrds
Steve

[Ken Layton]

Did you accidently break/crack the brightness/contrast controls? Any other compenents accidently get their leads pushed over and touching an adjacent component's leads?

Did a nut, washer, or bolt come loose from somewhere and land on the ciruit board or maybe even roll UNDER the circuit board?

[smac666]

Well it has a seperate little daughter board with six pots on it.
One of those was damaged (I think the bottom left with the wires facing up), but I replaced it straight away with an identical one.

I never thought of that, but I will double check tonight that it is the correct rating.
I'm sure it is, but you never know, I might have misread it.

Thanks for all your help so far.

Regards
Steve
 

[SirPeale]

Make *absolutely* sure you replace it with the correct rating, you don't want to damage your monitor.

[smac666]

I didn;t have a lot of time and I checked it last night.
It was the vertical hold pot and it had been replaced with the correct size.

Guess I'll keep trying

Thanks
Steve