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Old 02-15-2011, 12:04 PM   #141
smason
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Default Re: Dell E153FPB Back Light problem

Quote:
Originally Posted by EGuevarae View Post
???
At least it wasn't shorted.
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Old 02-18-2011, 05:16 AM   #142
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Default Re: Dell E153FPB Back Light problem

Hi again,

Thanks for the advice. I will do that.

i was thinking about doing a reflow of the solders using a heat gun (using my infrared thermometer to gauge temperature of the PCB). I fixed an IBM laptop that way (the one I'm using to type this).

Best regards,

Eric

ps. Sorry about the picture and the 'great resistance' thing was not meant to be funny, I am not a native english speaker and things can get warped in translation. I meant infinite resistance.

e.
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Old 02-18-2011, 11:27 AM   #143
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Default Re: Dell E153FPB Back Light problem

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Originally Posted by rukirie View Post
i was thinking about doing a reflow of the solders using a heat gun
Do not use a heat gun. Just use a regular soldering iron to remove the old solder and add fresh new solder.
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Old 02-18-2011, 12:33 PM   #144
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Default Re: Dell E153FPB Back Light problem

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Originally Posted by retiredcaps View Post
Do not use a heat gun. Just use a regular soldering iron to remove the old solder and add fresh new solder.
I agree. The idea is to change the solder,not re-melt it.
Reflowing applies to another kind of problems,mostly with BGAs.

And don't worry about the "great resistance" thing.Here besides helping each other,we have fun....
And about the non-English native thing,don't worry...My native language is Spanish and I've managed to get along pretty well so far (I think) ....
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Old 06-20-2011, 01:42 PM   #145
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Default Re: Dell E153FPB Back Light problem

New member here (2nd post).

I'm working on a Dell e173fpb that would not power up. The power switch/light would repeatedly blink and each time you could see a short burst of backlighting from the lower-left corner (two clues).

After pulling it apart, giving the boards a visual once-over and finding this post I checked the fuse (FP751) which seemed fine (jumping it caused no change). Next I tested the Q7x0 and Q7x9 transistors and found two (same side) that seemed shorted. After desoldering them I now have a monitor that functions on two lamps but only for a few seconds (screen appears then monitor shuts off, restarts OK). I've ordered a repair kit and will try to come back with an update after I've replaced the two transistors.

A close visual inspection of the boards (both sides) reveals nothing out of place. I'm about half-way through reading this thread so there may be some nuggets that I haven't found yet.

Anything else I should check while I'm waiting?

Cheers and thanks everyone!
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Old 06-20-2011, 01:53 PM   #146
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Default Re: Dell E153FPB Back Light problem

If you add a photo, perhaps we can see if it is an E173 OR an E153, which you have filed this under ???
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Old 06-20-2011, 01:56 PM   #147
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Default Re: Dell E153FPB Back Light problem

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Originally Posted by bcstedt View Post
Anything else I should check while I'm waiting?
1) You MUST resolder all the inverter transformer pins due to poor quality solder/soldering. A visual inspection may seem fine, but you MUST resolder them.

2) Check all c5707s and fu9024s for shorts.
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Old 06-20-2011, 02:55 PM   #148
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Default Re: Dell E153FPB Back Light problem

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Originally Posted by Rtech View Post
If you add a photo, perhaps we can see if it is an E173 OR an E153, which you have filed this under ???
The monitor model is an E173 (as stated in my post).
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Old 06-20-2011, 03:27 PM   #149
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Default Re: Dell E153FPB Back Light problem

Quote:
Originally Posted by retiredcaps View Post
1) You MUST resolder all the inverter transformer pins due to poor quality solder/soldering. A visual inspection may seem fine, but you MUST resolder them.
Oh you are SO right! Further inspection of the four inverter transformers joints (while slightly flexing the board) reveals at least five circular fractured joints.

Quote:
Originally Posted by retiredcaps View Post
2) Check all c5707s and fu9024s for shorts.
There were only four c5707s (two bad, two good). Did not see fu9024 but the other transistors seem to check out.

Thanks!
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Old 07-07-2011, 09:59 AM   #150
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Default Re: Dell E153FPB Back Light problem

Repair kit arrived yesterday and after re-soldering all four Xformers (bent the leads out for better electrical / mechanical connection) and replacing two c5707 Xsistors it is back up and running. Will burn it in for a day, but so far so good.

Many thanks to the forum and all those who've contributed here!
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Old 01-01-2012, 09:49 AM   #151
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Smile Re: Dell E153FPB Back Light problem

Hello & Happy New Year To All,

Can anyone give me a pinout for CN701 on the e153fpb (48.L0H02.A00).
I'd like to test for output voltages to logic board.

Thanks In Advance,
lcdman
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Old 01-16-2012, 07:44 AM   #152
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Default Re: Dell E153FPB Back Light problem

I have a E153FPB with a blurry display. I am not sure where to start because it is only blurry with the VGA input. If I have a signal coming in and click the menu button, the menu looks fine, but the backgroud VGA input is blurry. It almost looks like I can see the progressive scan. My first guess is the actually logic board for video input. What do you guys think... thanks for the help
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Old 01-16-2012, 02:59 PM   #153
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Default Re: Dell E153FPB Back Light problem

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Originally Posted by jschiefer View Post
I have a E153FPB with a blurry display.
Reseat and clean all your connectors with isopropyl alcohol.
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Old 01-16-2012, 03:18 PM   #154
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Default Re: Dell E153FPB Back Light problem

Quote:
Originally Posted by retiredcaps View Post
Reseat and clean all your connectors with isopropyl alcohol.
Okay, I tried that and it didn't work. I also tried a different cable and source. It has come to my attention that the longer the monitor is on, the worse it gets. It changes from blurry to lines running horizontally flickering up and down the monitor. I tried to take a picture but that did not do any justice.
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Old 01-16-2012, 03:46 PM   #155
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Default Re: Dell E153FPB Back Light problem

Also, When I hit the menu, the display stops flickering for the 2 seconds it takes for the menu to come up, then continues.
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Old 01-16-2012, 03:53 PM   #156
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Default Re: Dell E153FPB Back Light problem

Take it apart and post some pictures following the instructions in my sig file (earlier post).
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Old 01-16-2012, 04:29 PM   #157
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Default Re: Dell E153FPB Back Light problem

Okay, Here are some pictures. I took a bunch and these are the best. Hope they work. I had to resize them, I hope I didn't lose too much quality.
Attached Images
File Type: jpg b832.jpg (859.8 KB, 28 views)
File Type: jpg aa8b.jpg (1.08 MB, 11 views)
File Type: jpg 3fee.jpg (837.2 KB, 19 views)
File Type: jpg 5c4f.jpg (987.6 KB, 9 views)
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Old 01-16-2012, 04:50 PM   #158
retiredcaps
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Default Re: Dell E153FPB Back Light problem

There are 2 voltage regulators on the main/logic board.

1) List the part numbers off the chip.

2) With your multimeter, measure the DC voltage of each pin with respect to ground.

3) When the problem occurs, re-measure the DC voltage on each pin.

4) When the problem occurs, also measure the DC voltage of each connector pin between the power and logic board (yellow/red cable).

We are looking for any fluctuation in DC voltage to see if this is causing the monitor to flicker.
Attached Images
File Type: jpg 3fee.jpg (310.0 KB, 10 views)

Last edited by retiredcaps; 01-16-2012 at 04:52 PM..
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Old 01-22-2012, 09:13 AM   #159
jschiefer
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Default Re: Dell E153FPB Back Light problem

Okay, I got the measurements. I apologize. I didn't mean for it to that long, something came up.

Anyways the numbers on the chips are:
AIC 1084-33CM 584G3 (larger one) PDF Datasheet
BS18532G3 (smaller one) Maybe the end is 63? I couldn't find any information on this chip.

The first chip, (1084-33CM)
0v --- GND
3.26v --- Vout
4.69 --- Vin

The second, (BS18532G3)
0v ---
1.77v ---
3.24v ---

I think these are okay after looking at the datasheet.

Here is the molex connector coming from the PSU board to the video board.
Starting with the yellow pin at the (top)
Y-2.97
Y-2.89
Y-11.66
Y-0 ???
Y-5.05
R-0

I checked these measurements twice, and with a second meter. They are within .01v. The voltages didn't change when the monitor is more blurry than times when it is not.
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Old 01-22-2012, 12:22 PM   #160
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Default Re: Dell E153FPB Back Light problem

Quote:
Originally Posted by jschiefer View Post
I think these are okay after looking at the datasheet.
Yes, they are okay.

Quote:
The voltages didn't change when the monitor is more blurry than times when it is not.
Well, I'm out of ideas.
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