Dell E228WFPC goes dim after 10 minutes, not 2 seconds

[smalltownguy]

Re: Dell E228WFPC goes dim after 10 minutes, not 2 seconds

Does it stay on longer if you turn the brightness down?

Hm....I'll have to try that.

[selldoor]

Re: Dell E228WFPC goes dim after 10 minutes, not 2 seconds

Hi if your boards are the same there is a longish thread here:
http://en.community.dell.com/support...px?PageIndex=1

Initially they thought it was a heat problem on the pwm though replacment did not seem to fix. They then added an extra resistor which appeared to work for some but for others was only partial fix as part of screen remained dim. I dont think they bottomed out why the resistor helped but of you were to extract all the relevant bits and could find a schematic for your your board i am sure budm would figure it out. If you could find a voltage regulator that should keep the voltage down to around 2v that is not working then that might be the answer

Does it stay on longer if you turn the brightness down?

[Jasgriff]

Re: Dell E228WFPC goes dim after 10 minutes, not 2 seconds

You don't have to heat anything up to the extent that u might damage anything just enough yo replicate the fault which normally takes a few minutes.

[smalltownguy]

Re: Dell E228WFPC goes dim after 10 minutes, not 2 seconds

have you also checked the esr on the caps between the 2 heatsinks top right of picture?

Yes.

Before I try any hair dryer tactics, it would probably be a better idea to place my panel on the boards of a known working donor monitor. If the problem migrates, then I know it's a CCFL issue.

[vinceroger69]

Re: Dell E228WFPC goes dim after 10 minutes, not 2 seconds

have you also checked the esr on the caps between the 2 heatsinks top right of picture?

[jetadm123]

Re: Dell E228WFPC goes dim after 10 minutes, not 2 seconds

Sounds like a heat problem/ bad solder joint. Since you have 10 minutes before the problem occurs, may I suggest you try a hair dryer and heat up various portions of the power and logic boards to see if you can accelerate the problem. Hopefully, you'll be able to narrow down the board/area that's giving you the problem.

[Jasgriff]

Re: Dell E228WFPC goes dim after 10 minutes, not 2 seconds

Just read your problem and the other thread. That's a strange problem.

Its a shame you don't have some spare ccfls to eliminate that. I can't help but think that heat is causing the issue. You could try to leave the monitor off for sometime then slowly heat up an area of the board to see if that bring the symptoms on earlier. This could help determined where the issue might be for you.

[smalltownguy]

Working on a Dell 22" monitor I purchased from eBay. The monitor stays on for approximately 10 minutes, then goes dim. When it does go dim, cycling the power causes 2 seconds to black behavior. Leave the monitor powered off for a few hours repeats the ability to have it run for 10 minutes, then the issue reappears.

I've checked all the caps on the inverter board (Elite brand) with my blue ESR meter and all of them spec out fine.

I metered the blue caps near the transformers and got similar ohms between the two (secondaries, right?)

I DO have a few spares at work to check for possible CCFL failure, but I really don't want to pull apart another 22" panel that's in constant use unless I absolutely have to. These things are heavy and awkward.

My symptoms are similar to the ones described in this thread:

https://www.badcaps.net/forum/showth...light=e228wfpc

And, of course, pics: