Dell E176FPb - Only powers on for a few seconds

[drob]

Hi there guys.

I was hoping to get some help with the above Dell monitor. I've searched the site, but have only found threads that were related to lack of power.

I've also read the parts of the site where it suggests how to identify what could possibly be wrong with the monitor, but I haven't been able to identify any of it. All of the caps and solder joints seem to be in good condition.

Basically the problem is as it says in the title. When the monitor is powered on and connected, it will display fine for a max of 15 seconds, the will cut out to a black screen. The green light remains on though. If I cycle the power off and on again with the power button on the front of the monitor, it will then work for another 10-15 seconds, then cut out again.

If any of you gents would be kind enought to have a quick look at my attached images to see if you could identify the problem, that would be a huge help!

Thanks in advance for any help you can offer me

David

[retiredcaps]

Re: Dell E176FPb - Only powers on for a few seconds

This board looks like a Benq-ish design.

1) Resolder all the inverter transformer pins (T801, T802, T803, and T804). They can look okay, but be bad. Same for C824 and C826.

2) Q815 and Q816 are likely to be C5707s. Same for the ones near T801, but I can't make out the PCB designation.

3) Q805 and Q812 are likely to be FU9024s.

For #2 and #3, check them for shorts (not likely shorted, but check anyways). Resolder all these pins as well.

4) Although your monitor stays on for 10 to 15 seconds, this could be "2 seconds to black".

More details starting with post #13 and #14 at

https://www.badcaps.net/forum/showthread.php?t=10419

I would concentrate on the following areas

a) bad caps
b) bad secondary inverter transformer
c) bad ccfl
d) bad ccfl wiring
e) bad ccfl sense circuitry

5) Excellent clear focused photos.

[pr0cess0r]

Re: Dell E176FPb - Only powers on for a few seconds

its the same desing of power supply than my dell 17 inch lcd. All caps had good esr and the 4 C5707 tested ok but have a low Hfe reading. From all auction i see on ebay that sell the kit of those parts im tend to think its the way to fix those power supply. My kit is shipped i will give feedback when i install it!

(4) 2SC5707 Transistors
(2) FU9024N Transistors
(1) BEL 125V 3 Amp MS Fuse

[Lumberjack777]

Re: Dell E176FPb - Only powers on for a few seconds

its the same desing of power supply than my dell 17 inch lcd. All caps had good esr and the 4 C5707 tested ok but have a low Hfe reading. From all auction i see on ebay that sell the kit of those parts im tend to think its the way to fix those power supply. My kit is shipped i will give feedback when i install it!

(4) 2SC5707 Transistors
(2) FU9024N Transistors
(1) BEL 125V 3 Amp MS Fuse

Sounds good. Seems to be a widespread problem with that model, and the Benq's.
I've fixed several and it was always one of those components.
And like Retiredcaps says. "Make sure to resolder those inverter transformer pins"
They might look good. But resoldering them seems to make this repair last. Good luck!

L-J-7

[drob]

Re: Dell E176FPb - Only powers on for a few seconds

Hey Retiredcaps, pr0cess0r, and Lumberjack777, thanks for the replies so far.

Can I ask pr0cess0r, how much is this kit, and will it be worthwhile? There is a replacement board on ebay for £11, do you think this would be worthwhile, or am I going to encounter the same problems again further down the line? Although technically minded, I don't have much experience with soldering and such.

What would anyone suggest in my situation?

Thanks,

David

[Scenic]

Re: Dell E176FPb - Only powers on for a few seconds

http://cgi.ebay.com/220488756040

edit: failed to notice you posted about a replacement board in pounds.. http://cgi.ebay.co.uk/220488756040

[pr0cess0r]

Re: Dell E176FPb - Only powers on for a few seconds

if the fix work it can be reliable but if you dont do all the test needed its like lotterie. This particuliar board is very cheap and i fix mine just to learn.

[retiredcaps]

Re: Dell E176FPb - Only powers on for a few seconds

There is a replacement board on ebay for £11, do you think this would be worthwhile, or am I going to encounter the same problems again further down the line?

You will likely run into the same problems. We see A LOT of Benq boards with these inverter transformer solder problems, shorted c5707/fu9024, blown picofuse, etc.

There are many other websites that have the same documention/recommendations for these Benq boards.

Although technically minded, I don't have much experience with soldering and such.

Best soldering video is at

http://www.youtube.com/watch?v=I_NU2ruzyc4

If you are not comfortable soldering, get a friend to do it.

[rtm4040]

Re: Dell E176FPb - Only powers on for a few seconds

can i get data point in CN701 power board ?
i want to try connect my vga board with acer power supply.

My acer power board have info data in the connector example dimm, on off, grounding and 5V but in dell power board no info data.