Dell E171FPb Monitor Flickers

[Technoguy3]

So I was given a Dell E171FPb LCD monitor and told it "was flickering and then died". When I tested it myself, it certainly flickered (I couldn't get it to die though). It appeared to be the backlight rather than the LCD itself, but I'm not 100%. I opened it up, took off the caps from the power supply and board leading to the backlight, tested them, and replaced 1 bad cap. Still have the same issue. It appears to be working better (maybe it's just my imagination), but it still flickers. Any ideas? I can include pics of the board if necessary.

ALSO: One 1000uf cap was showing almost 1500uf on my tester. Could that be the problem?

EDIT: Forgot to mention there's a relatively high amount of "electrical" whine coming from the display. Does the backlight need replaced?

[Rtech]

Re: Dell E171FPb Monitor Flickers

Have you got a Test backlight ??

[sam_sam_sam]

Re: Dell E171FPb Monitor Flickers

ALSO: One 1000uf cap was showing almost 1500uf on my tester. Could that be the problem?

I would also replaced this one as well it is over ( 20% + or - ) just replaced them

20 % should not higher than 1200 uf

When I have seen this before the ESR goes up (.20 ) or more when the temp goes down and it changes a lot when you see a value over 20 % the value marked on the cap compared to a new cap when read the uf value it is may have the same value or a little bit lower than what the cap is marked and the ESR value only goes up a few .05 an then stay at a value

Just for fun dose it have a date when it was made

I hope this helps

[Technoguy3]

Re: Dell E171FPb Monitor Flickers

The manufacture date was March 2003.

Test backlight? I thought backlights in monitors were all proprietary.

[sam_sam_sam]

Re: Dell E171FPb Monitor Flickers

The manufacture date was March 2003.

I would replace ALL CAPS

[sam_sam_sam]

Re: Dell E171FPb Monitor Flickers

Test backlight?

A test backlight is just a CFL tuble the same size tube out of a broken monitor if you have one to test the monitor that you are working on

[budm]

Re: Dell E171FPb Monitor Flickers

Any pictures of the power/inverter board?
Home made test lamps:
http://s807.photobucket.com/albums/y...g%20old%20CFL/

http://s807.photobucket.com/albums/yy352/budm/DELL/

[sam_sam_sam]

Re: Dell E171FPb Monitor Flickers

Any pictures of the power/inverter board?
Home made test lamps:
http://s807.photobucket.com/albums/y...g%20old%20CFL/

http://s807.photobucket.com/albums/yy352/budm/DELL/

I am glad that you shared this that great way to make a useful tool

[Technoguy3]

Re: Dell E171FPb Monitor Flickers




The yellow stuff on the one capacitor on the power supply isn't leaking; it's just glue. lol

[budm]

Re: Dell E171FPb Monitor Flickers

Can you check those two lytic caps ESR and value on the inverter or just solder the caps in parallel and see the result?

[Technoguy3]

Re: Dell E171FPb Monitor Flickers

I don't have an ESR meter to measure it. Which caps are you talking about?

[budm]

Re: Dell E171FPb Monitor Flickers

The two electrolytics caps by your thumb in the second picture post 9.

[Technoguy3]

Re: Dell E171FPb Monitor Flickers

So the monitor will no longer actually show any picture..... I'm just going to call it BER and be done with it. I still don't know what's wrong with it.

[caphair]

Re: Dell E171FPb Monitor Flickers

This symptom in these monitors are usually caused by a shorted transistor that drives the back light circuit (inverter). I can't tell where they are from the pics you've provided but they're on the psu. I bet one or two of them are shorted and causing the psu to go into shut down mode.

[lionidas]

Re: Dell E171FPb Monitor Flickers

hello,

i'll have to dig out this thread again, sorry about that,,
i have the same Monitor and the same flickering issue,,

so any assistance would be great,

thanks

[budm]

Re: Dell E171FPb Monitor Flickers

hello,

i'll have to dig out this thread again, sorry about that,,
i have the same Monitor and the same flickering issue,,

so any assistance would be great,

thanks

Pictures of YOUR boards?

[lionidas]

Re: Dell E171FPb Monitor Flickers

hey, thanks for your reply,

the board is identical to the one in pictures above

[lionidas]

Re: Dell E171FPb Monitor Flickers

ok then, here they are,,

[stj]

Re: Dell E171FPb Monitor Flickers

it probably needs a full recap with panasonic FR, i'v had a few and the 15" version that needed that.

given the age, it probably has worn tubes too - but they are probably o.k. still.

lot's of probably's there, that's the nature of repair work

[stj]

Re: Dell E171FPb Monitor Flickers

ok then, here they are,,

that wont show on some browsers inc mine - upload them as attachments - no damned imgur or fotofucket.