Dell 3008wfp faulty power supply

[budm]

Re: Dell 3008wfp faulty power supply

it is not shorted otherwise it will show low ohm readings in both directions.

[selldoor]

Re: Dell 3008wfp faulty power supply

Ok so I suggest try and get some better photos of the boards so we can have another go at spotting problems. Then put it back together and try it again - do a resume of what happens from when you plug in via switch on to stable fault stage and say what you have done, tested, replaced. so that new readers do not have to piece it all together.

[fuus]

Re: Dell 3008wfp faulty power supply

Camera's I have at my disposal are:
iPhone 3GS
Canon 350D
Some point and shoot Canon thingy

Which would you recommend for this? I can't seem to get any of the cameras to correctly focus on the board..

[Wrog]

Re: Dell 3008wfp faulty power supply

Either of the Canons should have a macro mode (icon looks like a flower with two leaves). That will allow close-up focus.

[selldoor]

Re: Dell 3008wfp faulty power supply

I would use the canon 350 - instructions here
https://cdn.badcaps-static.com/pdfs/...d158f29a93.pdf

You are unlikely to get good pictures at night unless you have a lightbox
-probably best to wat til daylight tomorrow. Try it on macro - closeup as for flowers/insects - page 43 -46. Do not use flash

[7.62mm]

Re: Dell 3008wfp faulty power supply

Hello everybody

Just what the doctor ordered!

I was nearly going to throw my DELL away, if i wouldn't of been for this helpful site. And there is not even a fingerprint let alone the slightest scratch on mine, but she goes blank after turning her on and stays in that state now. Not forgetting to mention the heat she was producing whilst in use. Reminded me a little of a fan failure when lifting a car bonnet.

Right...Looks like i need a multimeter, soldering iron, ground lead and if someone has the spare part for sale that would be great


Thanks for reading and hopefully a PM from somebody here

Danny

[molar]

Re: Dell 3008wfp faulty power supply

Hello from me as well

My 3008WFP died a couple of weeks ago; just went 'tut' and then no power. I found this site but took it to a local repairers first who have told me that Dell want £350+VAT for a new power board!

So I too shall be ordering the Schottky rectifier and hopefully my soldering skills are not too rusty.

Thanks for all the usful information.

Andrew

[samuelmorris]

Re: Dell 3008wfp faulty power supply

I had something similar, £350+VAT from a repair place, managed to haggle them to £275, but still way too much.

Bought in a pack of STPS60170CTs, set to it with a soldering iron, and 1 week later, so far so good.
It's astounding that this is so reliably the cause of these failures...

[molar]

Re: Dell 3008wfp faulty power supply

All I can say is I am pleased to hear your success story (and those of the others who have taken the trouble to post here). It has made me wary of buying a large monitor from Dell again. I have a couple of 19" Eizos that must be at least 8 years or so old which have worked really well (and two Iiyamas but one of those had a dodgy power supply too that was fixed for £80). I suspect that they are designed better.

I think I need to practice my soldering skills though first before replacing the diode. I will let you know if I have been successful

[samuelmorris]

Re: Dell 3008wfp faulty power supply

Both my previous displays I sold to friends, a 2407FPW and 3007WFP. Both are still functioning fine at 6 years of age versus only 4 for my 3008 - I think this oversight seems only to extend to the 3008WFP version. At our LANs, almost a dozen people own 2407FPW displays from 2006-2007 and none have failed - the same is true of the one other owner of a 3007WFP. I'm not inclined to distrust Dell over this one flawed product, particularly because it is in a class of its own technology-wise. While there were several competing products to the original 3007WFP, the 3008/U3011 have none.
All the other Dell displays me and my peers have used have been excellent. As disappointing as Dell's poor out-of-warranty service is, it's not enough for me to condemn the whole company/product range yet.
Eizos are about the best in the business for build quality, so it doesn't surprise me yours are still going strong.

I wish to express my gratitude to the other posters in this thread, blindly following the advice here without any technical documents to hand or support from Dell I was able to sort the issue out. Thanks to you all

[Th3_uN1Qu3]

Re: Dell 3008wfp faulty power supply

It would be interesting to see if there are any other factors causing this issue. If you look at the first pages, someone replaced the diode with an identical one, and it failed again shortly. Only when a diode with a higher voltage rating was substituted, did the monitor work good again.

Since the monitor worked for years with the original, and then suddenly it blows it up AND also blows up another new diode of the same type, and will only work with a higher rated one, makes me wonder whether there isn't something wrong with the primary.

The only factors in the voltage spike atop the PWM waveform are:

• The transformer, which is unlikely to shift operating parameters - it either fails catastrophically (very rare occurence), or continues to work at the designed parameters the whole useful life of the device, so we can take that out.
• The snubber circuit - snubber resistors are sometimes selected with inadequate power ratings, and with age, they increase value or fail open. That's what i would suspect...

Anyway. If the snubber circuit is bad, don't worry about it, since there are quite a number of people that have proven that only the diode on the 24v rail is affected, and nothing else, so swap away with a 170v or 200v diode of the same, or higher current (amps) rating, and keep enjoying your monitor. The STPS60170CT is overkill for this application, but it does help keeping it nice and cool, so use it if you can get it. If this part isn't available in your area, just ask, and we'll help you find one that is.

It's just that it would be interesting for someone with an oscilloscope to identify the problem for sure.

[samuelmorris]

Re: Dell 3008wfp faulty power supply

This is the same somewhat disturbing revelation I had. There's a possibility that some other fault is being 'caught' by the blowing of this diode. It's the reverse voltage rating that makes the difference though it seems, not necessarily the current load from what I've seen.

Only guess I can think of is perhaps that the cooling isn't up to par for the diode, but how that would affect things I'm not sure.
In the UK at least with RS, the 40170 and 60170 were identically priced.

[Th3_uN1Qu3]

Re: Dell 3008wfp faulty power supply

The reason is definitely not thermal, otherwise a replacement of the same type would not blow that fast. Of course, since the diode now has to eat voltage spikes above its breakdown voltage, it'll run hot and die quickly, but that's the effect, not the cause.

[tom66]

Re: Dell 3008wfp faulty power supply

I would love to pick up a 3008WFP, but a 30" 1600p monitor isn't cheap, even as faulty. But it would be awesome to have.

Maybe there's one other possibility. If this monitor uses PFC, an ageing primary cap could be causing higher transients on the primary bus voltage (greater ripple, but also more susceptibility to line noise), which would translate to higher peak voltages.

If the snubber resistor fails, won't that take the primary MOSFET out in short order, or does it only affect the secondary?

[samuelmorris]

Re: Dell 3008wfp faulty power supply

A little off-topic, but older 3007WFP models can be found cheaper potentially, if you have the source to drive them - however, you do need a dual-link DVI output as the monitors lack any of the complex electronics of the 3008, and thus cannot interpret any signal other than native 2560x1600, which neither single-link DVI nor VGA can provide (there is nothing but one DL-DVI connector on the 3007).

Otherwise, the 2560x1440 U2711 represents a more affordable compromise (£520 new, £430 refurbished) that still offers the ability to interpret reduced resolution, analog and standard-def signals.

[Banano]

Re: Dell 3008wfp faulty power supply

Yet another recent failure here, though mine lasted just under 4 years before popping so looks like I had a better run than most.

Dell were of course, absolutely no help at all - I can't believe that if it was a day inside warranty they would courier out an advance replacement asap, yet offer NO out of warranty repair service and in effect told me to bin it. A £1000 screen!!!

If they'd told me a new PSU was £100 + labour I'd probably have paid it tbh but now I have a nice little (cheap) project once the new diode arrives.

Thanks in advance for all your efforts!

[Th3_uN1Qu3]

Re: Dell 3008wfp faulty power supply

If the snubber resistor fails, won't that take the primary MOSFET out in short order, or does it only affect the secondary?

If the primary switcher has a high enough breakdown voltage, no, it won't blow. It'll just work as normal, because from the point of view of the transistor, nothing happened. Basically, with high voltage transistors you don't need a snubber - but high voltage, high current transistors with low voltage drop/RDS(on) are expensive, so compromises are made.

On the other hand, if the secondary circuitry is designed with a certain peak voltage in mind, and that voltage is exceeded for whatever reason, trouble will ensue.

[Banano]

Re: Dell 3008wfp faulty power supply

Success! Replaced the diode and now I have my screen back!

Again, thank you all so much, there's no way I would have been able to do it without you!

[melvmay]

Re: Dell 3008wfp faulty power supply

Just wanted to stop by and let everyone here know that I have two of these 3008 WFP monitors and a few weeks ago one stopped working. Dell were, as expected, useless taking over a week to let me know that I'd need to purchase a new one.

I ordered two complete power supplies (in-case my other one died later) from Taobao however just over a week later I got an email saying it was out of stock.

So I purchased a few STPS40170CT Schottky 170V diodes without much hope that replacing them would work but earlier today I installed it and upon powering-up the unit I was elated to find that it worked and has been working with the cover on for several hours!

I can't thank everyone in this forum enough. Dell wanted £1000 for a new monitor, I spent £12.

[plasmod]

Re: Dell 3008wfp faulty power supply

Is there anyone in australia i can buy this STPS30170CT from?? the only website i found welling it is mouser and they want $40 for shipping!

this is what i found in jaycar but running at 100v only. is this something that might work? thanks in advance

http://www.jaycar.com.au/productView.asp?ID=ZR1039