Dell 3008wfp faulty power supply

[DSH]

Re: Dell 3008wfp faulty power supply

Hi All,

I have the same symptoms as KK325ic, that is, plug in power and get blue light ON, but nothing else. None of the buttons do anything, the blue light always remains ON. I have read all the great help on this site but not seen any solutions for this particular problem so far. I have the monitor apart and already replaced the D22 (STPS40170CT) but no change to symptoms. The boards all look to be in very good condition to me (I do a lot of electronics repairs). I have measured voltages for the 3 connectors with the T-con and inverter disconnected, as follows: I have used the "Good" PSU voltages from another post on here.
P801 (logic)
Pin | Good | Bad
1 to 5 5.2 5.2
6 to10 | 0 | 0
11 | 18 | 0
12 | 0 | 0

P802 (Logic)
Pin | Good | Bad
1 | 5.22 | 5.22
2 | 0 | 0
3 | 12.58 | 12.8
4 to 6 | 0 | 0
7 | 0 | 3
8 | 12.8| 0.05
9 | 0 |3.29
10 |5.2 | 1.72

P803 (Inverter)
Pin | Good |Bad
1 to 5 | 25 | 0
6 to 11 | 0 | 0
12 | 3.26 | 3.29
13 | 2.55 | 1.72
14 | 0 | 0

So I have 5V but no 12, 18 or 25V. Not sure where to go from here. Any help would be most appreciated. I have an ESR meter which I have used on all the caps I could see and all are A-OK.

[Agent24]

Re: Dell 3008wfp faulty power supply

Here are photos from two of my board. Here are symptoms 1) The blue LED is on as soon as I plug in the power cord. 2), I cannot turn the blue LED off using power button. 3) the screen is black.

Is there any additional test can help pin down the problem?

Can you check the voltages on all pins of the two connectors diagonally opposite the mains input socket on the PSU?

List the connector names\pin numbers and the voltages you measured please.

[Agent24]

Re: Dell 3008wfp faulty power supply

Hard without a schematic.

There are tons of regulators on the mainboard. It would make sense to check all these first.

Find the standby rail from the power supply. Find out which regulators it goes to. Are they all getting the standby power and outputting the correct voltage?

[GlenC]

Re: Dell 3008wfp faulty power supply

I've been reading these threads, but don't see a list of possible effects of the failure of D22. Other than the entire screen going blank, what other symptoms may appear as D22 starts to fail?

My 3008WFP was working just fine, then one day, I turned it on and the screen didn't come on.... I recall the right half having some wide very dark blue vertical lines....

any thoughts?

thanks

[Ricambi]

Re: Dell 3008wfp faulty power supply

It's alive!

Thank you all for a great thread, without this I could not have succeed to rescue my DELL 3008 WFP monitor, replaced the faulty D22 Diode with STPS40170CT... . Small part with a huge effect on the monitor....

[math]

Re: Dell 3008wfp faulty power supply

I have another dell 3008 that doesn't power on.

I turn it on with the button, blue light says it's on, but black screen. no display. I held a light up to the screen to see whether it was a faulty backlight, but nothing

I've replaced the D22 diode as well, the same diode that i used to fix my previous screen.

[ranjit8083]

Re: Dell 3008wfp faulty power supply

Hi, I've just come across this Thread, I've had a Dell 3008WFP monitor for a 7-8 years but now suddenly doesn't power up. I was wondering if anyone would be able to fix it for me. I can try taking the power supply unit out and posting for repairing if anyone can help me on this? Im not too keen on soldering as i've never done any previously and don't want to risk damaging it further. Please let me know if anyone can help and how much it'll cost.
Many Thanks
Ranjit

[kk325ic]

Re: Dell 3008wfp faulty power supply

One more photo for the front view of the main board.

[kk325ic]

Re: Dell 3008wfp faulty power supply

Here are photos from two of my board. Here are symptoms 1) The blue LED is on as soon as I plug in the power cord. 2), I cannot turn the blue LED off using power button. 3) the screen is black.

Is there any additional test can help pin down the problem?

[Agent24]

Re: Dell 3008wfp faulty power supply

I replaced D22 and put everything back together. The monitor has blue light, but don't response to any button and no floating block of color bars. Is there any diagnostic procedure that I can go through to pin down other problem?

Where to check the standby voltages and voltages to other control boards?

Need photos of your own board etc.

[Agent24]

Re: Dell 3008wfp faulty power supply

Hi Agent24

Thanks heaps for the response. On which points should I take measurements ?

Would it be possible for you to mark the points on the screenshot

Also what mode should I set my multimeter to?

Best regards,
M

Please take more photos showing both sides of the whole board, so I can see where all the parts are and if there may be some visible damage anywhere.

[kk325ic]

Re: Dell 3008wfp faulty power supply

I replaced D22 and put everything back together. The monitor has blue light, but don't response to any button and no floating block of color bars. Is there any diagnostic procedure that I can go through to pin down other problem?

Where to check the standby voltages and voltages to other control boards?

Another observation: 1. blue LED is shown when the power is plugged in. 2) cannot turn off the monitor without unplugging the power.

[maatsche]

Re: Dell 3008wfp faulty power supply

Do you get any standby voltages with this PSU? Or any voltage across main filter capacitor?

Hi Agent24

Thanks heaps for the response. On which points should I take measurements ?

Would it be possible for you to mark the points on the screenshot

Also what mode should I set my multimeter to?

Best regards,
M

[kk325ic]

Re: Dell 3008wfp faulty power supply

Do you get any standby voltages with this PSU? Or any voltage across main filter capacitor?

I replaced D22 and put everything back together. The monitor has blue light, but don't response to any button and no floating block of color bars. Is there any diagnostic procedure that I can go through to pin down other problem?

Where to check the standby voltages and voltages to other control boards?

[Agent24]

Re: Dell 3008wfp faulty power supply

Do you get any standby voltages with this PSU? Or any voltage across main filter capacitor?

[maatsche]

Re: Dell 3008wfp faulty power supply

Hi guys,

First off thank you so much for contributing to this thread everybody.
I also happen to have a not powering on 3008 sitting around the house. Recently I was given a another 3008 in working order and started trouble shooting the faulty monitor with the parts of the working monitor.

No surprise, I was able to get the old monitor working with the power supply from the working monitor I receive.

As per this thread I bought the correct replacement part for D22 and put everything back together. Unfortunately, the monitor still won't power on also there is no blue light.

I then took everything apart again and resoldered the 3 diodes which needed to be removed, but without success.

Compared to the working PSU the broken PSU doesn't even have some kind of a “drizleing electric noise” when inserting the power cord.

It would be so much appreciated If you could you please have a look at the photos attached and give me some ideas where to continue looking for the fault.

Thanks so much!

[Lumberjack777]

Re: Dell 3008wfp faulty power supply

OK. I sent you an email. Thanks. I'm a gambling man

[TTLKurtis]

Re: Dell 3008wfp faulty power supply

Haha yeah I mean who knows which part is bad on it, I certainly don't. I know some use a multimeter to try and find bad components, but I'm not sure what I'd be looking for and I also have no desire to open that thing again since I already have a replacement.

But hey, if you want it, I do have this 32" Samsung monitor box sitting in my garage... Make me an offer plus shipping and it's all yours.

Email kurtis[at]kurtiskronk[dot]com

[Lumberjack777]

Re: Dell 3008wfp faulty power supply

OK. You can always put it on eBay for parts. I know a guy that was looking to buy a main board from a broken Dell 3008. (unless it IS the main board problem on this!) heheheh

Actually I might buy it just for parts.

[TTLKurtis]

Re: Dell 3008wfp faulty power supply

It's alright - definitely plugged everything in properly. This is the same behavior it exhibited before I opened it up. On the plus side, I feel pretty confident in my ability to desolder and solder stuff now!

I went ahead and replaced it with a Samsung S32D850T 32" monitor, and I'm pretty happy with that decision for only $519.