Viewsonic P810 Clicking

I had a P810-1M monitor. Im not sure if it is different from yours. Check the FCC number. Mine is GSS21001 August 1996 It has the same chassis number. I do have a service manual and schematic for mine. Check the FET transistor that drives the flyback transformer. E-Mail me if you need more info. John

Thanks for the reply John,

My FCC ID is GSS21001 August 1997, so same number but a year younger if that makes a difference.

I've done some testing against a manual that I found on the 'net and it seems that I am getting only 14vDC at Q820 (2SC4620) where I should be getting 125vDC!

This transistor seems to drive IC820 (STR-S6531) which I can't seem to find any information on.

However, when I connect my multimeter between any side of R806 (336vDC) and earth (on volts DC scale), the clicking stops and the degauss circuit seems to operate as normal!

I have the thing in a million pieces right now so I don't know if the screen is actually working when the clicking stops so I can't say for sure, but it seems to temporarily cure the problem.

I'm going to investigate this a little closer but any further help would be greatly appreciated.

Regards,

Kevin :)

I got power back to the mainboard, but as predicted the flyback is now the problem.

I'm running through all the supporting components to see if it is merely a supply problem.

Kevin :)

I tested the secondary side of the flyback with both diode and resistance tests (+ve and -ve directions), both show open circuit.

The primary side is good.

So I guess it's new flyback time :(

Any suggestions on where to get one?

Kev.

Actually it sounds like your flyback is just fine, the HV rectifier diode has a forward drop quite a bit higher than a multimeter can supply, so it'll test open circuit. If it's testing low impedance then you have a problem.

Well that's good news about the flyback.

My greatest problem right now is that I cannot test a pulsing voltage.

I have a problem flow chart but I need to be able to test a 0 to 47v pulse and I only have a standard DMM.

Any suggestions on how to do this?

Regards,

Kev.