Re: Dell E176FPb 17" LCD No Power!



Thanks for the suggestion...will just do that asap...in the meantime I have identified equivalent transistors for SMD W06 = 2N3906 & W04 = 2N3904... ...

Re: Dell E176FPb 17" LCD No Power!

I have identified Q602 with marking W06 and Q603 with marking W04. Further checks indicated that SMD transistor W06 is PMBS3906, a PNP 40V 100ma general purpose PNP transistor manufactured by Phillips. The same is for W04, which is actually PMBS3904.

My problem is where to buy such SMD transistors as its not available here. Just wondering whether I can substitute W06 with 2SA812 and W04 with BC307 transistors. Any suggestions out there?...

Re: Dell E176FPb 17" LCD No Power!



Thanks for your alert.
Nearly missed it...since it is so small.
Any idea on the code for this SMD transistor Q602, which is located on the bottom of the circuit board (green color) or a similar one normally used for Dell 17 inch Lcds by Benq?...

Re: Dell E176FPb 17" LCD No Power!



Actually...the Dell board is the white one..while the brown board is Benq...if you are talking about Q601 (I don't see any Q602), I forgot to inform that I removed it for checking purpose.

Pls. focus attention on the first 2 pictures attached, which is from the Dell power board, while the 3rd pix from Benq (Brown color) is only for comparison purposes......

Re: Dell E176FPb 17" LCD No Power!



Attached pls. find the pixs of the top and bottom part of the Dell E176FPb inverter board. I also included for comparison a pix of the Benq FP716G+ (which have similar schematics) most of the parts are still intact except for 2 pcs of C5707 and 1 0.22uf 160v capacitor which I have removed earlier.

As mentioned, the 4 C5707 and the 2 P-Channel Mosfet IRFU9024 transistors are missing from the Dell board! Can I confirm that this board doesn't need these transistors to work...or my nagging suspicion the an unscrupulous...

Re: Dell E176FPb 17" LCD No Power!

According to my friend, what happened was one day was he tried turning it on and it wouldn't work, the light on the power button wouldn't on at all and it just seemed to die like that. Wasn't because of lightning or surge because he said that he use a surge protector and never on his computer in a thunderstorm.

Further asking around came out with the suggestion that the SMPS could be a problem but comparison with a similar Benq inverter board using a multimeter didn't show a transformer problem...Could it be... there is a defective...

Re: Dell E176FPb 17" LCD No Power!

On checking further I found a TL1451 IC in place of the 4 missing 2C5707 mosfet transistors in the inverter circuit...could this be the problem?

I have a Dell E176FPb 17" lcd manufactured by BenQ. It will not power on i.e. there is no light on the power button. I have taken the panel apart and examined the power inverter board and found that it does not use the common p channel Mosfet C5707 eventhough the circuit board has blank spaces for them?. There are no bulging capacitors, found the 2A 250V pico fuse burned and one of the Bridge Rectifiers faulty. Replaced the fuse, bridge rectifier and 0.22uf 275V capacitors but still could not get it working. Anyone have any experience with this LCD panel or problem? Appreciate if anyone also...