Dell E153FPf Power Issues

[high-tech]

The PFC never comes up on this one. the back light is dimly lit and you can turn it on off with power button. The voltage on C845 never gets over 160 volts DC.
Im pretty sure that when power supply is on I should meter around 400 volts DC.

ANY HELP WOULD BE APPRECIATED THANKS.

[selldoor]

Re: Dell E153FPf Power Issues

Cant see any pfc on this board ? 160vdc seems about right.

[selldoor]

Re: Dell E153FPf Power Issues

What happened at C504 - there is a very thin line trace goes under it looks like one end is
on that large connector in top right corner - where does the other end go and is it conductive.

[budm]

Re: Dell E153FPf Power Issues

There is no PFC circuits in this old 15" Dell. The main filter shoucl have about 165~170vdc.
@selldoor, where do you see the C504? You must be using you super PC magnifier again!

[selldoor]

Re: Dell E153FPf Power Issues

Looking at the front of the board its the top one on the right - the damage is on the back
of the board.
@budm - I enlarge the pics by clicking then when they are as big as they will go I use
ctrl and + keys to blow till it blurs

[budm]

Re: Dell E153FPf Power Issues

OK, I zoomed real close and see it now, thanks.
The two traces on the top connector to the LCD panel with C504 positive leg conected to them are tied together and it also goes to the Collector of Q501, the Emiter of Q501 is connected to the Output center pin of the U801 (Adjustable regulator). I believe Q501 is the switch for VCC for the LCD panel T-CON board.

@high-tech: What DC voltage do you have at this cap without turn on the monitor?

[retiredcaps]

Re: Dell E153FPf Power Issues

Tthe back light is dimly lit and you can turn it on off with power button.

Check U1 and U2 for shorts.

[selldoor]

Re: Dell E153FPf Power Issues

@budm - I really meant the thin line trace that goes between the legs of the cap I have dotted it in on the attached.

[budm]

Re: Dell E153FPf Power Issues

Oh, on the bottom side, darn you have good eyes!