Dell 2007FPB teardown

[mikesq1982]

Re: Dell 2007FPB teardown

I just wanted to thank everyone for sharing their knowledge and experience. I was able to fix a 2007 FPb just now using this resistor replacement technique.

Thanks again

Mike

[ptg21]

Re: Dell 2007FPB teardown

Sorry if it's bad form to drag out an old thread. I just feel compelled to add another success story to the list and a huge thanks to ac21 and budm.

I picked up a 2007fpb a few weeks ago for $10. After getting it home and hooking it up, it was exhibiting random restarts and shutdowns. There would be sporadic periods that it would remain fine for upwards of 1hr, but then it would revert back to rapid series of restarts, basically rendering the monitor unusable. I didn't have time then to investigate so I put the monitor aside until just recently. By this point, it was completely dead and no longer powered on.

I've done a few "repairs" in the past where I had replaced failed electrolytic capacitors in other monitors/electronic devices. These were always easy to spot and replace. But the complexity of this 2007fpb is on a completely different level and frankly was overwhelming. I read through several forums and threads and was intimidated by the sheer number of probable issues and related components. Moreover, the sad truth is my skill level and soldering iron are not adequate for the newer, smaller, denser surface mount components. So the idea of having to tinker with so many of these tiny delicate components made the task seem impossible.

However, finding this thread was a huge boon. The pics from budm are an excellent reference. The key discovery though was the 2.7k ohm resistor under the "dielectric" glue on the usb board. Confirmation from other users that it was the cause of their issues gave me hope -- a chance of needing just one single "repair" to get my monitor working correctly. Sure enough, the suspected resistor was dead when I uncovered and tested it. Now I just had to replace it. But this was still a problem as I didn't have any replacement nor did I have any realistic chance of desoldering/resoldering SMDs anyway... Undeterred, I ended up jumping two through-hole resistors in series onto the existing surface mount resistor. No, I didn't even bother to remove the old one. I had to use two in series b/c I didn't have any single resistors at or near 2.7k ohms.


Amazingly... it all worked! The monitor works perfectly now.

Again, a huge thanks to ac21, budm, and the entire badcaps board. I hope others are able to use this thread to revive their own 2007fp monitors. Such an amazing monitor for $10. If these issues are as common as they seem, it would be such a waste for these monitors to be discarded due to such a trivial issue.

[rassystems]

Re: Dell 2007FPB teardown

ok thansks....

[selldoor]

Re: Dell 2007FPB teardown

Rasystems - please start a new thread - this thread is meant to be for
reference only

[rassystems]

Re: Dell 2007FPB teardown

Hi,

Can i connect 19v from a external power source to check the USB board(5EL2J08001 USB/DC Converter board)

If i can connect means what should be the Volt have to come ?

[pandekripa]

Re: Dell 2007FPB teardown

A feedback from MR. KALMARA was best
and i am able to make one monitor working

regards
thank you sir

[tweety]

Re: Dell 2007FPB teardown

Thanks very much.

I had a monitor that would not switch on. After changing all the caps on the power board I found this thread and the faulty resistor. I ripped apart a faulty surge arrestor to scavenge parts and stole a 2.2K surface mount, soldered it in place of the faulty one identified in the post. I now have a working monitor!

Luckily I have two of these monitors so i was at least able to narrow it to the board in this thread but only after i'd changed all the power board caps! Oh well at least its fixed now. I should have searched more as i doubt the caps were faulty as they all looked good.

THANKS !!!!!!

[Tusitas]

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.

Same problem here, Thanks for posting it

[levesqu6]

Re: Dell 2007FPB teardown

using this and the other information posted elsewhere in the forum i was able to fix one of these monitors. Specifically the information posted above by ac21.

Symptoms:
After moving monitor to another desk, it started restarting itself randomly. The frequency increased over a afternoon until the monitor would not stay on long enough to be usable as a second screen.

Diagnosis
I took the monitor apart and looked for obvious damage and bad caps. Found none. Looked for the 19V and the all important 3.3V rail created by the USB board. I found that when the monitor restarted this rail dropped to near 0V. I checked the diodes and generally poked around. After reading ac21's experience and a few other posts on the forum, i decided to peal back the glue above the set of surface mount resistors. I checked the one marked 272 and found it to be a open circuit.


Fix:
I replaced the resistor marked 272 with the nearest value i had around (2.1k) and the monitor works flawlessly again.

I hope this helps someone else.

[aortiz]

Re: Dell 2007FPB teardown

you are right,its amazing what this web can do for people now,i am retired living in mexico,and you are all the way in italy bringing an oportunity for me to learn something else.i had a co-worker,very good friend of mine,called frank zukiki,he was italian,i think from sicili,he is also retired,i dont know if he went back to italy.
anyway,are the other pins on this transformers supposed to read a short? like pin 2 to 7 and 3 to 6? i guess i unsolder the transformer to see if its something else on this pins that make it look like shorted.

[Davi.p]

Re: Dell 2007FPB teardown

Is not only the help, but the opportunity to learn something for me.. (whitout reading big, difficult, not clear and expensive guides fo electronics)

[aortiz]

Re: Dell 2007FPB teardown

thank you davi.p,i contacted the site and all of the sudden the blue "new thread" button was there.i think it had to do with my previleges as a new member,i was doing something or did something wrong,or did not do as requested.
i was able to start a new thread just a few minutes ago.
its so good there is good people like you willing to help a total stranger in trouble.
thank you

[Davi.p]

Re: Dell 2007FPB teardown

browse through the forum tree, when you find this on top of the therads list there's a blue button to the left..

[aortiz]

Re: Dell 2007FPB teardown

pardon my ignorance but i dont know how to post a new thread,i looked all over the place for the "NEW THREAD" tab and cuouldnt find it,sorry,can you please help me with that? i am new at this forum thing .
thank you

[selldoor]

Re: Dell 2007FPB teardown

Aortiz - Please start your own thread. post good clear pictures of your boards front and back.

[aortiz]

Re: Dell 2007FPB teardown

i have a dell 2007WFPb that dont light up,the on light stays blue,and i can see what i think is the backlight(very dim,i think)you can only see it with the room lights off,i have some limited electronics knowledge,have a digital fluke 79 series2 multimeter,a soder sucker,solder wick,a 35 watt soldering iron,and very little knowledge on lcd monitors,but i do want to learn and can follow instructions,worked in california for some 20 years or so,as an electronics tech on a rapid transit system ,very mechanical oriented work more so than electronic,parts changer basically,i did get an as degree in electronics but that was some 30 years ago or so.anyway what do you recomend i start checking,and please poit out the name of the boards too.
please help.

[budm]

Re: Dell 2007FPB teardown

The buck regulator switching power supplies are on the board where the USB ports are. You can see 3 TOROID inductors on that board.

[aortiz]

Re: Dell 2007FPB teardown

are buck regulators a circuitry on a board ?,or that is the name of the board? if so, which board is it of the 4 boards?

[aortiz]

Re: Dell 2007FPB teardown

As this is a brand new forum, I thought I'd open up a thread to encourage new members to introduce themselves a bit.. now hey.. let's not get too personal.. ok ?

And if you wouldn't mind to keep this thread \"clean\" let's try to keep the the chitchat (i.e. even the welcome to the board replies) to a minimum or this thread may get to 100 pages fast

So I'll start things off :

My name is petabyte and I'm a forum junkie. :oops: I've been off the wagon for a number of years and countless times I've tried to stop but it's useless.. I need to feed my learning addiction.. :!:

Now just a bit about me.. I'm a fairly secretive guy in terms of privacy on the net.. especially when the things you write are visable to anyone with a net connection. But I love to share the info and knowledge I have, so that's why I'm here, to share and learn.

my formal education is that of an electronic engineer and I held a field service position with a firm for over 20 years.. that job is gone now along with company car and laptop <cry> oh well..
So needless to say (but i will) I've always tinkered with things.. yes, a hacker.. (too bad that term lost it's orignal meaning) a hardware hacker mostly.. hacking fixes in whatever I find that breaks.. (except for cars, I have friends for that) I got started a little late into the computers, my first box was an ibm pc-xt with a whopping 10meg HD,blazing fast 4.66mhz 8086 processor, 640k mem running dos 3.3.. man was I cool back then.. :roll: nevermind..

so these days, I'm forced to be a software guy as well.. as I fix pc's for friends and that usually means cleaning virus/trojan/adware and reinstalling OS's.. yeah hardware breaks but not that often :cry: so as a result, I keep up on my software knowledge by visting a few security forums.. and trolling around a few hardware forums as well.

now I found this place from a thread at motherboards.org/forums
where I've been hanging out lately.. it's a nice friendly place with some pretty smart people.. mostly, of course, it's about mobo's.. So this person mentioned badcaps.net and I recalled reading articles a year or so ago about the faulty caps and was curious as to what you guys were up to.. and I said \"w00t.. they have a forum\"..

and so now.. you're stuck with me :P

so what's your story ? come on.. give it up..

After reading the https://www.badcaps.net/forum/showthread.php?t=10658
on Dell 2007. I found 2 of them today and took them apart to see how it is put together.
What I found are:
1) It only has one always on DC power supply output of 19V.

2) The 19V is fed to the Backlights inverter board.

3) The 19v is also fed (J4) the USB Hub/3 Buck converter regulators (3.3V (Q6) for the Logic board where the VGA/DVI, control panel are, 5V (Q14) (this 5V is also fed into 3.3V linear regulator for the USB interface IC) for the 4-port USB hub (these 4 USB ports are protected by 4 fuses), 12V (Q9) for the powered speaker bar DC output jack. This 19V is fed through 3A fuse. MOSFETs Q6, 9, and 14 are 2SJ598, P-Channel.

4) If the USB/Buck converter is not connected, the monitor will not work.

5) The 3.3V output from the Buck converter is fed back into the logic board which feeds U13 (1.8V Linear regulator) and U5 (2.5V Linear regulator) to run the LOGIC IC's on the logic board.

6) One bad design in the Buck regulator is that they parallel 2 Schottky Diodes together (http://electronics.stackexchange.com...des-a-bad-idea) to try to get more current handling, but if you do not precisely match the Vf of the Diodes, the one with lower Vf will be on, the one with higher Vf may not be on at all. They should have use single 2 or 3A rating Diode instead of 1A rating, Diodes are rated at 1A 40V. This may explain why this model has the same failure mode due to shorted out diodes.

are buck regulators a circuitry on a board ?,or that is the name of the board? if so, which board is it of the 4 boards?

[ac21]

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.