LG Flatron W1934S, 2 sec to black

[joeh]

I guys ihave this monitor, and it come black after 2/3 seconds powered or vga cable plug in.
I have test all caps on power board andits are ok.
i have test twice inverter pin 8-7 t501/t502 all are good no sound with digital tester.
What can i do???
Thanks

[Jasgriff]

Re: LG Flatron W1934S, 2 sec to black

Do you have and spare working ccfl`s so that you can test to see if that's the issue?

[joeh]

Re: LG Flatron W1934S, 2 sec to black

no i don't have it.

[Jasgriff]

Re: LG Flatron W1934S, 2 sec to black

You could take a look at Budm's guide to making one out of an old CFL.

https://www.badcaps.net/forum/showthread.php?t=19987

[selldoor]

Re: LG Flatron W1934S, 2 sec to black

What do you mean by

i have test twice inverter pin 8-7 t501/t502 all are good no sound with digital tester.

Please tell us the ohms measurement on each transformer

[joeh]

Re: LG Flatron W1934S, 2 sec to black

pin 7 and pin 8 are the secondary of inverter transformer, and i read on its with tester in diode mode 0.609, 0.620. If one of t501 or t502 are faulty the tester beep with any value or 1.000.

[selldoor]

Re: LG Flatron W1934S, 2 sec to black

Yes. However the actual measurement is more important than it simply working. The two transformers have to have secondary wiring resistances that are within 3% of each other. I think Diode scale is the same as Ohms
but perhaps you can check them again just to be sure Set meter on 2000 ohms scale.

Another "trick" that sometimes works is to try plugging the lights into
different sockets as the top lights tend to wear out first.

Please can you update your profile with the country you are in and mains voltage.

You need to read this retiredcaps guide
https://www.badcaps.net/forum/showthread.php?t=10419

start at post#19

[retiredcaps]

Re: LG Flatron W1934S, 2 sec to black

pin 7 and pin 8 are the secondary of inverter transformer, and i read on its with tester in diode mode 0.609, 0.620. If one of t501 or t502 are faulty the tester beep with any value or 1.000.

When testing secondary windings, we are looking for breaks in the copper.

Doing a diode test is a good idea, but we generally suggest, as selldoor mentioned, an ohms measurement so we can see if the windings are within 3% of each other. This guideline was suggested by PlainBill below

https://www.badcaps.net/forum/showpo...7&postcount=18