Dell 2007FPB teardown

[Behemot]

Re: Dell 2007FPB teardown

I got another piece of this display and unlike the previous two (or was it three?), I do not think this one ever saw the sound bar. However, there was no +12 V anyway. Is it actually supposed to be on all the time, or is it activated only when the bar is plugged in??

[dftntm]

Re: Dell 2007FPB teardown

Kinda big one, no?

Yeah

It is a 1 watt resistor. Now I am quite confident that the monitor will become obsolete before that resistor burns open any more.

[Behemot]

Re: Dell 2007FPB teardown

Kinda big one, no?

[dftntm]

Re: Dell 2007FPB teardown

I had a 2007wpb that wouldn't turn on at all unless i let it sit plugged in for a few hours..then it would turn on long enough for the "no signal message to come on" then die again it would repeat this randomly.

After reading kalmara's post i checked the row of resisters under the "white blob of dielectric" on the usb board .. the first one is a 2.7k (printed on it 272) i first jumped a resister of unknown value across it and the monitor started working. then i desoldered the SMD and soldered in a regular 2.2k resister and put it back together ..everything is working great so far.

I read a bunch of post here and there but couldn't figure it out so i made this post so people in the same situation can do the same but maybe you should replace it with the right resister

here are some pictures of the location on the resister thanks to budm.

Thank you very much. Here it is how I solved, following your advise, the not working monitor issue:

[paddlestroke]

Re: Dell 2007FPB teardown

After re-trying, it appeared that those strange problems were induce because I applied ground on the screw hole. When applying GND on the pin header (pins 5-6 from left) they disapeared.

Then I could see the problem : only 5V was working, 3.3V and 12V are off.

In the end I found the problem it was 3 SMD resistors that were out of specs (153, 010 and 473) in the row of SMD under the white dielectric blob. Just upside the right PWM IC on my picture.
I found out comparing the resistances values read with ohm-meter between the 3.3V PWM circuit (that was not working) with the 5V PWM circuit (working).
- 153 (15k) and 010 (10k) were clearly open circuit
- 753 and 473 did not read the same values between 5V PWM and 3.3V PWM.
So I unsoldered all that were not the same as on the 5V to check them. Result was 753 was ok (75k), 153 010 and 473 were open-circuit. (473 should be 47k ohm)

I replaced them with new SMD resistor and the 3.3V came back.

I did not fix the 12V as I don't need it. Although I tried but I saw no differences in the SMD resistors of the PWM (with 5V PWM) so I did not knew what else to do.

Hope this might help someone sometime

[paddlestroke]

Re: Dell 2007FPB teardown

Hello,

I have one of these LCD and it does not turn on.

Reading through those pages I tried to find the error, but no luck so far.

I looked for exploded caps on all boards but nothing obvious. Then I focused on the USB board as all errors on this topic seems to come from there.

I tested the resistors under the white bulb, but none is deffective. 3A fuse is not blown. Zener I am not sure how to test them. When I use diode on my multimeter I read 0.160 and all paralleles pairs of diodes read the same.

I wanted to test voltage output without having the 220V plugged in so I used my laboratory powersupply and tried to apply 19V directly on the board input (before the fuse) in order to check 5V and 3.V

Something quite strange happens:
- first time I did it there had been a shortcut appeared between 19V and GND, so my laboratory powersupply voltage droped. I unconnected. Then I could still measure the shortcut between ground and 19V. Few minutes after the shortcut was gone.

- second (and other) time I plug in 19V when my 19V electrod come close there is a strong spark, but after the spark it seems normal. The voltage do not drop as first time. And I do not have a shortcut between 19V and GND anymore...
But on all converter bucks Q6 Q9 and Q14 I read 19V both on the input and the output



Should'nt I be reading 5V 3V and 12V on the converter output?
I am not very good yet with debugging electronics so maybe I'm missing something big! Please let me know if this gives you any idea.

[tempvoid]

Re: Dell 2007FPB teardown

Hey, guys!

Thanks for "272" resistor hint.
Dell 2007FP (2008 year) didn't turn on since few days ago. Now works as new!
Official Dell service in Kyiv, Ukraine: won't fix (read as "go buy newer one").

ac21 and others
https://www.badcaps.net/forum/showpo...3&postcount=12

[DeFi]

Re: Dell 2007FPB teardown

Thank you very much for this informative teardown! Thanks to this I was able to fix my friends 2007WPb with the "no power at all" symptom. The cause was an defective 47K smd resistor at R52 under the white thermal glue on the USB board.

[DeFi]

Re: Dell 2007FPB teardown

Thank you very much for this informative teardown! Thanks to this I was able to fix my friends 2007WPb. The cause was an defective 47K smd resistor at R52 under the white thermal glue on the USB board.

[expertpc]

Re: Dell 2007FPB teardown

The 2.7K resistor on the bottom is testing good on my unit but there is a 15k marked 153 that is open. So be sure to test the rest!

[Yugga]

Re: Dell 2007FPB teardown

Hi, thank you for this thread. I successfully fixed my Dell 2007FPB with a 2,2K resistor taken from a graphic card. It works so far but I have not tested it during a long time so I do not know if this reparation will last.

[wdrummond]

Re: Dell 2007FPB teardown

I replaced the 272 resister but still now power button light. Has anyone found any other likely suspects for this monitor? Mine is the 2007wfpb. Thanks.

[dseselectric]

Re: Dell 2007FPB teardown

I just wanted to thank all involved for this post.

I was after an old monitor to use on a CCTV system. Being a cheapskate (as I am), rather than buy one, I popped to my local waste & recycling centre and found one of these babies on the scrap pile. As it looked in good nick, I whipped it onto the van, but on getting it home found it wouldn't power up.

I popped her open to check internal fuses and PSU caps all to no avail, then I came across this thread. Sure enough, that 2.7k resistor was open circuit, but I found a suitable candidate on a scrap PIR sensor.

Seems funny that something so small should bring the whole thing to its knees. I assumed it would be a PSU fault and never imagined it would be a resistor hidden under a glob on the USB board.

Still, I'm an electrican by trade, not an electrical engineer, so 230v cables and nuisance tripping RCD's are my cup of tea. I doff my hat to you chaps though; you really know your bananas!

Cheers,
David.

[Radek]

Re: Dell 2007FPB teardown

Thank you all, Could not have done it without you
Yesterday afternoon and half a night was well spent. Ordered power supply from eBay for my 2007FPb 1200x1600 monitor, but that was a $40 bust. That was not it. Combing internet and
Finding Badcaps, measuring values on four boards components, I came across the defective resistor. Found 2.7K resistor in my parts supply and soldered it in. not the prettiest soldering job, but guess what it works.
Cheers,
Radek

[lappen]

Fixed another 2007 WFP

Hey guys,

i just fixed another 2007 WFP by replacing the 2,7 k resistor. Thx for the information. It was really hard to solder this little tiny resistor out and solder the new in... didnt really think it would work but it did.

[johnz16]

capacitors

Budm, you made a post #129 abought samsung capacitors for ln52a550 tv the capcitors look the same but have different part numbers so witch one goes on top and witch one goes on the bottom I CHECKED AND ONE IS 35-OHM AND THE OUTHER IS 70-OHM ??thanks,john

[budm]

Re: Dell 2007FPB teardown

Might as well resolder those 3 post so it will not fail like the original one, the AC inlet is not well mounted and supported so plugging and unplugging the power cord at the inlet will weaken the joints seen too many of them failed.

[Behemot]

Re: Dell 2007FPB teardown

Kinda expensive, new connector should cost like a buck and than it only needs some soldering and silicone tricks (or something similar)

BTW recently I've been disassembling the speakers I got which blew the +12 V rail. I think the reason is obvious…all caps were like 99 baloons. So next time before you connect those Dell speakers to your expensive display, always recap that thing first! You'll save yourself lot of troubles. And test them with external +12 V source lol

[rdagger]

Re: Dell 2007FPB teardown

Thanks everyone for the advice. I found a new OEM power board on eBay for $25. Popped it in and my display is like new.

[rdagger]

Re: Dell 2007FPB teardown

It's burned too close to the ground, replacing won't fix that. Besides, there is almost nothing left from the copper pad, where would you like to solder it??

You're correct the solder pad is gone along with most of the outlet post.