Dell E172fpb again

[370forlife]

Well, the one I fixed and (mostly) recapped is acting up again.

This time it will flash a picture of the windows desktop for a second, then go straight to black with the power light on solid.

I read a couple of posts saying this is might be a bad backlight. I replaced all the caps on the power board except for 3 35v, 470uf elite's, they aren't bulged at all but who knows with elite.

Could I try hooking up the screen from one of the others and see if it works then? Problem is I don't even know if those ones work either.

[PlainBill]

Re: Dell E172fpb again

Well, the one I fixed and (mostly) recapped is acting up again.

This time it will flash a picture of the windows desktop for a second, then go straight to black with the power light on solid.

I read a couple of posts saying this is might be a bad backlight. I replaced all the caps on the power board except for 3 35v, 470uf elite's, they aren't bulged at all but who knows with elite.

Could I try hooking up the screen from one of the others and see if it works then? Problem is I don't even know if those ones work either.

Substitution is always a valid way to troubleshoot these problems. Using another panel, using other CCFLs, using another power supply / inverter are all ways of determining where to look.

Ideally, measuring the voltage and current to each CCFL would quickly pinpoint the problem area. Unfortunately, meters which will survive, let along give meaningful results with signals ranging from 650-1000 Volts at 100Khz are rather expensive. Measuring the return line may be possible - my $20 DMM from Harbor Freight is specified as measuring AC signals up to 400Hkz. Just make sure you don't hit the wrong pin on the connector.

PlainBill

[Mohonri]

Re: Dell E172fpb again

Have you tested the inverter transistors? That's the most common failure mode I've seen. Check out this thread for more information.