Dell 3008wfp faulty power supply

[hopper577]

Re: Dell 3008wfp faulty power supply

Hi,

I also have the same problem with my 3008WFP!!! Am just trying to get the parts to fix it today but being a public holiday makes it hard.

It seems as though the standard part people are using is STPS40170CT (40A), is there any advantage/disadvantage if I was to use STPS60170CT (60A)?

I replaced my D22 with a STPS40170CT from RS components. Got a pack of 5 for $23.76(AUD) delivered.

Hi Timo, You wouldn't happen to be in Brisbane by chance and want to sell me one of those diodes you have today?

Thanks
Ben

[sra15548]

Re: Dell 3008wfp faulty power supply

Well I managed to replace the diode....got it all back together and I get power now! No video though. Any thoughts?

[retiredcaps]

Re: Dell 3008wfp faulty power supply

Well I managed to replace the diode....got it all back together and I get power now! No video though. Any thoughts?

Reseat and clean every connector whether you touched it or not.

[fuus]

Re: Dell 3008wfp faulty power supply

I'm a complete noob to this business so please don't flame me!
How can I test the monitor to check if I have the same problem with mine? Plug it in and see if there is current over the diode?

[fuus]

Re: Dell 3008wfp faulty power supply

bump?

[fuus]

Re: Dell 3008wfp faulty power supply

I managed to dis-assemble the monitor, and have extracted the PSU. I have tested this with a Multimeter, and managed to short out the D22 Will this have caused any damage to the circuit? Thanks, Fuus

[Curamrda]

Re: Dell 3008wfp faulty power supply

Hi,
i am affraid that i can join to this group

My 3008 wfp yesterday died. Power light just went off and now I have nice 30" black screen for 1000USD at my desk ... fckng amazing...

Have already somebody done some DIY or tutorial how to replace that D22?

thanks

[Lumberjack777]

Re: Dell 3008wfp faulty power supply

Hi,
i am affraid that i can join to this group

My 3008 wfp yesterday died. Power light just went off and now I have nice 30" black screen for 1000USD at my desk ... fckng amazing...

Have already somebody done some DIY or tutorial how to replace that D22?

thanks

It's been awhile since I did that repair. But what I did was take out the power supply. It had heat shields and things to take off. But what I did was unsolder 2 or 3 capacitors that were in the way to access the diode. Unscrewed the diode and unsoldered it. Used some tweezers to pull it out. Put in the new diode. Screwed it in. Soldered it. Then soldered back in the capacitors that were in the way. It reminded me of the game of operation. But it saved me a lot of time with those heat shields and all. Good luck! L-J-7

[Curamrda]

Re: Dell 3008wfp faulty power supply

OK. I will try cut my monitor on weekend. And try get out the PSU. Than it would be easy I guess.

One question left. I am from Europe...so I have 220V electricity. And the STPS40170CT is up 170V right? isnt that problem?
Has anybody that STPS40170CT ? Coz i dont want to order 5 pieces :]

[Rtech]

Re: Dell 3008wfp faulty power supply

The 170V is not affected by your mains voltage.

[Curamrda]

Re: Dell 3008wfp faulty power supply

OK. Now only get some shop where they have the STPS40170CT in stock and not charge 40$ for shipping....

[Th3_uN1Qu3]

Re: Dell 3008wfp faulty power supply

Any similar rated diode will do.

[Curamrda]

Re: Dell 3008wfp faulty power supply

has anybody pictures how to get down the back cover? I have put off the from aluminium and now i dont know how to get the psu from back...

[hopper577]

Re: Dell 3008wfp faulty power supply

has anybody pictures how to get down the back cover? I have put off the from aluminium and now i dont know how to get the psu from back...

If you have the front bezel off your monitor all you need to do is turn the monitor over so the screen is face down BE CAREFUL otherwise the panel will fall out! Once you have the whole thing facedown you should be able to lift off the back panel. You may have some trouble where the Card Reader and where the Power socket is but should be able to flex the cover enough to pry these out.

[Curamrda]

Re: Dell 3008wfp faulty power supply

yeah.thanks. I've finally put the panel out. Cut the motherboard...and now i am fighting with the power board. I have get out all of screws... but it holds there like a biaaatch... and cant get out the power board...

[BlackBriar]

Re: Dell 3008wfp faulty power supply

Hi everyone,

I've had the same issue regarding the 3008 - one day my monitor simply shut off and is now dead to the world.

I've scoured a lot of forums, and found some really good source of info, especially in this thread and on Hard Forums. However, I simply do not have the engineering or technical ability to remove and re-solder components. I have looked everywhere for a repair shop that could work on my monitor, but all I get is the "buy a new one" stock response.

Does anyone know of anywhere in the D.C. / Virginia / Maryland area that could repair the monitor if they had the correct parts (that I can provide)?

Failing that, if anyone would like to make me an offer for the monitor then just P.M. me, as it's in great condition aside from the obvious flaw!

Grateful for any advice you can offer.

[jetadm123]

Re: Dell 3008wfp faulty power supply

Hi everyone,

I've had the same issue regarding the 3008 - one day my monitor simply shut off and is now dead to the world.

I've scoured a lot of forums, and found some really good source of info, especially in this thread and on Hard Forums. However, I simply do not have the engineering or technical ability to remove and re-solder components. I have looked everywhere for a repair shop that could work on my monitor, but all I get is the "buy a new one" stock response.

Does anyone know of anywhere in the D.C. / Virginia / Maryland area that could repair the monitor if they had the correct parts (that I can provide)?

Failing that, if anyone would like to make me an offer for the monitor then just P.M. me, as it's in great condition aside from the obvious flaw!

Grateful for any advice you can offer.

Suggest you look for any technical trade school or junior college in your area that offers electronic tech degrees. Speak to the instructor and I'm sure they can find a student to perform the soldering for you.

[jambam]

Re: Dell 3008wfp faulty power supply

Hi Guys,

I just want to share my ordeal with the 3008 .. My monitor just died same as everyone 1st week of June and when we took it apart the diode was indeed shorted.

My challenge was getting the suggested part STPS40170 , as I was in the Philippines , I didnt fancy the 5 pcs minimum order plus the 3 week wait .

So basing on information from this tread

1. It was an output schottky diode , which I verified while checking the location of the diode
2. voltage ouput was about 14v
3. Current at about 4 amps

I consulted a friend who has worked on PSU's for 20 years and he told me that the most important spec to consider was the trr or reverse recovery time w/c was a function of the switching speed , he said a slow diode was prone to heat up and quickly die in this application , he also said that a margin of 3 x the current and 4 x the voltage would be fine..

This opened up a lot of possible replacements for me so I found the BYV32E which was locally available for USD 1.50.

I'm keeping my fingers crossed , but I am on my 3rd week with this part in the monitor I use daily

My thanks to all that contributed to this tread which made the repair so much easier for a very expensive monitor

[Th3_uN1Qu3]

Re: Dell 3008wfp faulty power supply

BYV32E is also a suitable replacement in terms of recovery time and rated voltage (which i suspect is what kills the original diodes in these things, not the current capability). Good luck.

[budm]

Re: Dell 3008wfp faulty power supply

Some of the reason Schottky diode is used: No Trr, low Vf.
http://en.wikipedia.org/wiki/Schottky_diode
Reverse recovery timeThe most important difference between the p-n and Schottky diode is reverse recovery time, when the diode switches from conducting to non-conducting state. Where in a p-n diode the reverse recovery time can be in the order of hundreds of nanoseconds and less than 100 ns for fast diodes, Schottky diodes do not have a recovery time, as there is nothing to recover from (i.e. no charge carrier depletion region at the junction). The switching time is ~100 ps for the small signal diodes, and up to tens of nanoseconds for special high-capacity power diodes. With p-n junction switching, there is also a reverse recovery current, which in high-power semiconductors brings increased EMI noise. With Schottky diodes switching essentially instantly with only slight capacitive loading, this is much less of a concern.

It is often said that the Schottky diode is a "majority carrier" semiconductor device. This means that if the semiconductor body is doped n-type, only the n-type carriers (mobile electrons) play a significant role in normal operation of the device. The majority carriers are quickly injected into the conduction band of the metal contact on the other side of the diode to become free moving electrons. Therefore no slow, random recombination of n- and p- type carriers is involved, so that this diode can cease conduction faster than an ordinary p-n rectifier diode. This property in turn allows a smaller device area, which also makes for a faster transition. This is another reason why Schottky diodes are useful in switch-mode power converters; the high speed of the diode means that the circuit can operate at frequencies in the range 200 kHz to 2 MHz, allowing the use of small inductors and capacitors with greater efficiency than would be possible with other diode types. Small-area Schottky diodes are the heart of RF detectors and mixers, which often operate up to 50 GHz.