Dell 2007WFP Constant On/Off

[al.rob]

Re: Dell 2007WFP Constant On/Off

Thanks for the tip, POM_MJ, as I would have never figured out that tiny resistor on the USB board would be the cause of the cycling issue. I checked, and sure enough the resistor in my monitor was open. Not having another tiny resistor like that, I carefully tacked on a regular striped red-purple-red 2.7K resistor in place of that tiny one and the monitor is working again.

I don't think that the stuff you have to scrape away is glue, as there is nothing there that needs to be held with glue. I am guessing that it is some sort of thermal compound designed to conduct heat away from those resistors, which must be overstressed, so they tried to correct it with the glue-like substance. Maybe that is why this resistor fails. At least now I have a full-size resistor in there now. Thanks again for the tip.

[Yoder]

Re: Dell 2007WFP Constant On/Off

And another thank you! I removed that microscopic 272 resistor and tied a 4300 and a 7500 ohm resistor together in parallel to get a 2.7k ohm, wrapped in shrink wrap and soldered it in!

The whole thing took a few hours but I learned a lot and it seems that the monitor is working! No more continuous shutdown and restart cycles.

Thanks!

[diif]

Re: Dell 2007WFP Constant On/Off

Have you got a soldering iron ? It might be worth trying to replace the resistor POM also mentions.

[IamPK]

Re: Dell 2007WFP Constant On/Off

Like POM mentioned, all i did was remove the glue, over the last 24 hrs monitor has not given me any issues so far. Maybe it's just that glue and over time it heats up around that area and causes monitor to turn off and on repeatedly. Will know more if after a week or month later my monitor does not shut off on its on!

Also it could be the fact that i have not plugged in the USB ports on the side to the board. Figured i do not use the USB ports anyways so might as well not connect them.

Update: Spoke too soon it seems like its dead again, maybe on ebay i will find one with cracked screen and replace various boards and see what happens.

[cristian]

Re: Dell 2007WFP Constant On/Off

I've the same issue one, and fixed by myself.

1. I've remove all glue circled in the picture.
2. replace the chip resister code 272 (2.7K, 0603, arrow pointed).

hope this reply could help.

ps. original pictures are from this thread => https://www.badcaps.net/forum/showthread.php?t=10658

Thank you POM_MJ for help, your solution has worked in my case.
Before, i changed all the capacitors from the power supply board, without any result.

[ofwood]

Re: Dell 2007WFP Constant On/Off

Thank you POM_MJ, your solution solve my problem random redémarage of my DELL 2007wfpb.

[POM_MJ]

Re: Dell 2007WFP Constant On/Off

I've the same issue one, and fixed by myself.

1. I've remove all glue circled in the picture.
2. replace the chip resister code 272 (2.7K, 0603, arrow pointed).

hope this reply could help.

ps. original pictures are from this thread => https://www.badcaps.net/forum/showthread.php?t=10658

[maniacmechanic2004]

Re: Dell 2007WFP Constant On/Off

did you ever get this resolved? I am having the exact problem!

[suparfly]

Re: Dell 2007WFP Constant On/Off

I haven't. but I haven't had time, Ive been busy with christmas, then on business trips, then my hdd crashed and I had to make that the priority to recover. (which was successful!!)

I still need to reflow more components :S

[cato]

Re: Dell 2007WFP Constant On/Off

Having the same issue as well. I reflowed all the major components with no luck. I haven't done the small smd on the back of the board. Did you ever resolve your issue?

[dumpystig]

Re: Dell 2007WFP Constant On/Off

Sorry about the late reply.

Yep, you're nearly there, but whilst heating each joint add a small amount of fresh solder. Let us know where you're up to with the monitor now.

[suparfly]

Re: Dell 2007WFP Constant On/Off

hey Dumpystig. Just to make sure Im on the same page, my definition of reflow is just to heat the existing solder on a pad until its melted, and then allow it to cool again. hoping that if there was a poor contact, it will be fixed.

If thats about right, then I reflowed all the chunky components, and replaced all the caps. on the power board.

no change.

[dumpystig]

Re: Dell 2007WFP Constant On/Off

I've just updated my thread...

[trebo]

Re: Dell 2007WFP Constant On/Off

ING_193 is inverter board, re read this by Dumpystig

[suparfly]

Re: Dell 2007WFP Constant On/Off

Thanks for your suggestions, upon visual inspection, nothing looks bad. the caps all look healthy and so do the solder points. but Ill start with klkmaliks suggestion.

I read through dumpystigs post, but what I got out of it was that you changed all the caps, and then re-soldered all the joints and it worked. Im not as practiced at soldering as many of you are and am concerned I'll do more damage than good but Im gonna try.

PS: I took pictures and then realized I could probably just refer to the ones already on this thread. I assume this issue resides on the power supply board so thats where I am going to focus my efforts. The one board has me stumpted in regards to its purpose, I think its also power. picture IMG_0193.

[retiredcaps]

Re: Dell 2007WFP Constant On/Off

See my recent thread > https://www.badcaps.net/forum/showthread.php?t=17913

Similar off/on loop of Dell logo/Power LED. been working fine now for 8-9 days.

Sometimes, I can't put 2 + 2 together.

[dumpystig]

Re: Dell 2007WFP Constant On/Off

See my recent thread > https://www.badcaps.net/forum/showthread.php?t=17913

Similar off/on loop of Dell logo/Power LED. been working fine now for 8-9 days.

[retiredcaps]

Re: Dell 2007WFP Constant On/Off

Good suggestion on resoldering the various components. Try that BEFORE measuring the high voltage cap. It will be a lot safer and easier to do.

[klkmalik]

Re: Dell 2007WFP Constant On/Off

Last year I had some problem . i resolder invertor tranformer, high voltage side component and suround area , working fine try now i hope this will help u>

[retiredcaps]

Re: Dell 2007WFP Constant On/Off

For starters, if you have a multimeter with aligator clips, clip the leads onto the large capacitor 180uF 450V and arrange the boards so that nothing shorts out (use cardboard as insulator if required).

When the power led goes on/off, see if the large capacitor DC voltage readings drop or not. If you are in North America, it should be a constant 165 V DC.

If you have min/max feature on the multimeter, now would be a good time to use it.

Warning, this is high voltage and you are measuring the hot side which is why I'm recommending aligator clips.