Benq FP71G+ Led Power Off

[luigi]

Hi everyone,
congratulations for this board, it's reach of good informations and tips.

The monitor seems died: it is black and the power led is always off, when clicking on it.

I've removed the "case" and on the power board i founded the greatest capacitor had a lead cutted and all corrupted by electrolyte. It is an unfaumous Elite 450V/100uF.

I'll try to remove all the others Elite cap and some others element, trans, fet & transformers, and pico fuse, too.

Next time i'll give you the results.
Thank you for this infos.


luigi

P.S. Sorry i've no camera now to take photos: I'll try to remedy one.

[pedro]

Re: Benq FP71G+ Led Power Off

Hi everyone,
congratulations for this board, it's reach of good informations and tips.

The monitor seems died: it is black and the power led is always off, when clicking on it.

I've removed the "case" and on the power board i founded the greatest capacitor had a lead cutted and all corrupted by electrolyte. It is an unfaumous Elite 450V/100uF.

I'll try to remove all the others Elite cap and some others element, trans, fet & transformers, and pico fuse, too.

I wouldn't recommend removing anything (other than electrolytic caps) until we can see some good quality pictures of the boards. Many of the other components on the power board which can lead to your symptoms can be tested in circuit initially.

If the main (large) electrolytic is kaput, you certainly will get a "no LED, no pic, no sound" result. We don't know yet if it was the culprit or a victim - the cap failure can be due to its own shortcomings (Elite) or a bridge rectifier fault. Certainly test the bridge and also the incoming line fuse.

Invariably I would routinely replace all(*) electros once I had a monitor opened. (The large ones I generally don't replace unless they show a problem, as you report is the case with your unit).

Pictures please, as advised in so many threads.

[luigi]

Re: Benq FP71G+ Led Power Off

Thank you for the replay.

Morning Monday, i'll buy a digital camera to take some photos ...

[pedro]

Re: Benq FP71G+ Led Power Off

Thank you for the replay.

Morning Monday, i'll buy a digital camera to take some photos ...

BUY? Crikey Luigi, that's going to be an expensive monitor repair if you have to BUY a digital camera. I realise you may have other uses for it, but can't you BORROW one from a friend long enough to take a few pictures of the monitor boards?

[luigi]

Re: Benq FP71G+ Led Power Off

Oh, i mean a web cam, not too expensive, i have no one.

What do you think, would it suffice to take some photos of medium-high quality, especially with low or no blur?

Otherwise i contact a friend with a real digital camera, so to have good photos.

[pedro]

Re: Benq FP71G+ Led Power Off

Oh, i mean a web cam, not too expensive, i have no one.

What do you think, would it suffice to take some photos of medium-high quality, especially with low or no blur?

The webcams I've seen won't give us enough detail to help you.

Otherwise i contact a friend with a real digital camera, so to have good photos.

Yes please.

[luigi]

Re: Benq FP71G+ Led Power Off

Hello i'm here again.
I've soldered the following components:
J.J. capacitor 400V/100mF in place of Elite 450V/100uF
Bridge rectifier KBL408 4A in place of 2LKPM06M 2A
Fuse 2AT in place of 2.5AH

But when i plug the pw, i get an eletric arc near the transformer T601 of the PWM Controller.
What should i do next? My knowledge on feedback theory is gone from long time!
Greetings!

P.S. Can the capacitor be the problem? Usually this type is used in the amplifier stage of audio systems and so probably pushes too much current.

[cpp]

Re: Benq FP71G+ Led Power Off

hola!!

the 8pin IC pwm controller is a ncp1200ap40?

can you post photos of your board??

thanks!

[luigi]

Re: Benq FP71G+ Led Power Off

Yes it is.
Soon, next days, whenever possible i hope to post the photos, so to close my problem and this unresolved open thread.

Ooops, a typo error in the capacitor:
JJ is 400V/100uF