Dell E153FPB Back Light problem

[jschiefer]

Re: Dell E153FPB Back Light problem

So I read pretty much the entire thread and im afraid im still not sure where to start. I have the Dell E153FPB. When i turn on the LCD screen it flashes white for a second and then goes black. I cannot see any image on the screen but the LED power light stays on.
I tested the fuse PF751 with an ohm meter and it has resistance, so im thinking its not that.
I also flipped the board over and didnt see any cold solder joints, fixed a couple that were debatable.

Sorry if this is a double post. I couldnt look any longer lol

[freakytiki4u]

Re: Dell E153FPB Back Light problem

Excellent idea!

[EGuevarae]

Re: Dell E153FPB Back Light problem

I think I angered it. When I put the board back in to test it started smoking from the actual corner of the screen itself. LOL, Im just going to call this one a bust. Thank you for your patience with me. Until next time

Save the monitor. You can use parts of it to test (or even fix) other unit(s).
I have a box (not too big, but still a box) full of either received dead units, units killed by me in the name of science, or killed by others and donated to me. That box is a very precious resource sometimes ...

[PlainBill]

Re: Dell E153FPB Back Light problem

I totally know what ya mean, I've been married 3 times. LOL

Some people learn faster than others. At one time I introduced my wife as 'My first wife.' She retaliated by referring to me as her 'starter Husband.' I decided to refer to her as 'My trophy wife.' Things got a lot calmer after I came to my senses.

PlainBill

[freakytiki4u]

Re: Dell E153FPB Back Light problem

I totally know what ya mean, I've been married 3 times. LOL

[PlainBill]

Re: Dell E153FPB Back Light problem

I think I angered it. When I put the board back in to test it started smoking from the actual corner of the screen itself. LOL, Im just going to call this one a bust. Thank you for your patience with me. Until next time

Sometimes sacrifices are necessary. When it's a burnt offering, it's better to sacrifice a monitor than and human - well, some humans.

PlainBill

[freakytiki4u]

Re: Dell E153FPB Back Light problem

I think I angered it. When I put the board back in to test it started smoking from the actual corner of the screen itself. LOL, Im just going to call this one a bust. Thank you for your patience with me. Until next time

[PlainBill]

Re: Dell E153FPB Back Light problem

LOL, too funny, Thank You Sir and Im sending a cup of Joe your way

There are three possible causes of this problem. The power supply itself; the inverter,or the logic card. The only time I saw something similar was when their were shorted transistors in the inverter. This overloaded the power supply. HOWEVER, you have determined the 5V supply is stable. Next you can eliminate the inverter as a cause. This is the datasheet for the two ICs (actually paired power mosfets). Check each section of the pair for shorts. Check the resistance between D1 and G1, between G1 and S1, and between D1 and S1; repeat for D2 and G2, between G2 and S2, and between D2 and S2. Do this for BOTH ICs. If there are no shorts, unsolder one end of the jumper I have circled in the attachment. This completely isolates the inverter from the power supply. Now test the board in the monitor - no need to hook up the backlights. All we're interested in at this point is the behavior of the green power light.

The other two possible causes are the logic board, or more bad caps in either the power supply or the logic card.

PlainBill

[freakytiki4u]

Re: Dell E153FPB Back Light problem

LOL, too funny, Thank You Sir and Im sending a cup of Joe your way

[PlainBill]

Re: Dell E153FPB Back Light problem

you wont tell anyone I did that will you? LOL

Of course not. If I did, you would tell everyone the TV story.

PlainBill

p.s. We'll get back to the monitor once I wake up.

PB

[freakytiki4u]

Re: Dell E153FPB Back Light problem

you wont tell anyone I did that will you? LOL

[freakytiki4u]

Re: Dell E153FPB Back Light problem

Yeah I knew that. (tries to avert your gaze) LOL , tested again with DC (ahem) and this time it showed 5 volts (bangs head on desk.)

[PlainBill]

Re: Dell E153FPB Back Light problem

I checked again on 50 volt range with analog meter, still reading 10 volts, checked on 10 volt range reads maxed out, just a hair over 10 volts AC

AC??? It should be DC.

PlainBill

[freakytiki4u]

Re: Dell E153FPB Back Light problem

I checked again on 50 volt range with analog meter, still reading 10 volts, checked on 10 volt range reads maxed out, just a hair over 10 volts AC

[PlainBill]

Re: Dell E153FPB Back Light problem

Voltages are solid 10 volts testing each pos with all 3 neg. Same 10 volts on all.

Numbers on IC's are the same. Each has 4501GM and S05034 (might be 505034, hard to tell they are so small)

10 volts is a problem. It should be 5 volts. If you were using an analog meter it might be on the wrong range (user error), but if it's a digital meter and set on the 20 volt range, that's an accurate reading. 10 volts may have fried the logic board. BIG trouble.

PlainBill

[freakytiki4u]

Re: Dell E153FPB Back Light problem

I did not have the bulbs hooked up when testing voltage incase that makes a difference but it was hooked to the logic board.

[freakytiki4u]

Re: Dell E153FPB Back Light problem

Voltages are solid 10 volts testing each pos with all 3 neg. Same 10 volts on all.

Numbers on IC's are the same. Each has 4501GM and S05034 (might be 505034, hard to tell they are so small)

[PlainBill]

Re: Dell E153FPB Back Light problem

Wow, ty, very very easy to use and free, cant ask for more than that! lol Pics are attached as you asked ofr.

I've edited the picture of the bottom of the power supply. The first step is to measure the output voltage. The red lead of your meter goes to the pins at the upper right I've circled in red, the black to the pins circled in black. This should be done with the power supply hooked to the logic board of the monitor. It may be easier to probe from the top.

I also circled two ICs in blue. If these were shorted it could cause the problem. What is the part number of the ICs?

PlainBill

[freakytiki4u]

Re: Dell E153FPB Back Light problem

Try Fotosizer. You drop in an image, specify a new size either in percentage of the original or in pixels, and it resizes it either replacing your original or saving it to another place (or the same place with another name). It is what I sometimes use when I have to meet size (either in Kb or in pixel dimensions) reqs.
Eduardo

Wow, ty, very very easy to use and free, cant ask for more than that! lol Pics are attached as you asked ofr.

[freakytiki4u]

Re: Dell E153FPB Back Light problem

will do, ty very much