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Old 06-04-2011, 04:46 PM   #1
thewzard
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Default Dell 2407WFPb Monitor - Bad Cap

Hey All,

I have a problem on my hands! I have a very beautiful (and also very dead) 24 inch monitor that has a bad capacitor on the power supply. However, thats not really the problem. The problem is that the capacitor that died is the big kahuna -- 450V 120uf Elite branded capacitor -- and I can't find a replacement for it anywhere.

I'm trying to find a replacement capacitor so that I can attempt to fix this monitor. I've done a lot of reading on the matter but I simply don't know enough to make a decision on which capacitor to buy and where to buy it. I need your help, this is beyond my area of expertise.

Any help is greatly appreciated!

EDIT: Subscribed to the thread...
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Old 06-04-2011, 04:56 PM   #2
retiredcaps
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Default Re: Dell 2407WFPb Monitor - Bad Cap

Quote:
Originally Posted by thewzard View Post
The problem is that the capacitor that died is the big kahuna -- 450V 120uf Elite branded capacitor -- and I can't find a replacement for it anywhere.
Elite doesn't have the greatest reputation here so it is good that you cannot find that brand.

If you are in the USA, digikey has a good selection.

Goto digikey.com. Check the "in stock" box at the search engine.

Type in "450v 120uf 105" in the search field. 105 signifies 105C capacitor.

Narrow down the choice between Panasonic or Nichicon (either is fine but Panasonic is a favourite for many here). Look at the other specifications like diameter and height to find the cap that fits your board. Shipping from digikey using USPS First Class Mail should be around $2.75 USD.

PS. The best video on soldering is by CuriousInventor at

http://www.youtube.com/watch?v=I_NU2ruzyc4

Badcaps.net also has an excellent written (with photos) tutorial on soldering at

http://www.badcaps.net/forum/showthread.php?t=485
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Old 06-04-2011, 05:00 PM   #3
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Default Re: Dell 2407WFPb Monitor - Bad Cap

I forgot to mention that depending on the age of the monitor and quantity/quality of the rest of the caps, most here may suggest replacing ALL the electrolytic caps with name brand low ESR caps made by Rubycon, Panasonic, Nichicon, and United Chemi-con.

Capacitors die from age, heat, and shoddy build quality. Capacitors DO NOT have to be visibly bloated in order to bad. They can be out of tolerance uF (a 1000uF measures 20uF) and/or have high ESR (ohm). A multimeter will be insufficient to test for ESR. For that you need an ESR tester which costs between $50 and $300.
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Old 06-04-2011, 05:45 PM   #4
thewzard
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Default Re: Dell 2407WFPb Monitor - Bad Cap

Hey retiredcap,

Thanks for the information! I have actually tried digikey.com but my measurement puts my cap's diameter at ~17mm and I can't find anything underneath 20mm and the space around that capacitor is quite crowded if you know what I mean. I'm not saying it won't work. A 20mm cap might fit but its a tight space is all I'm saying.

On the bright side, the height doesnt seem to be a problem...
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Old 06-04-2011, 08:23 PM   #5
retiredcaps
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Default Re: Dell 2407WFPb Monitor - Bad Cap

Quote:
Originally Posted by thewzard View Post
my measurement puts my cap's diameter at ~17mm

On the bright side, the height doesnt seem to be a problem...
Maybe this one?

http://search.digikey.com/scripts/Dk...me=565-1470-ND

It is 18mm x 35.5mm (diameter x height). Now it is a 400V DC cap versus 450V DC.

Most of the newer 20" or higher lcds have two supplies and probably use PFC. With PFC, the voltage across the main cap can be high as 380V DC. I haven't personally seen anyone report anything over 400V DC.

So the 400V DC cap could work, but there is less margin for error.

I'll check some other sites.
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Old 06-04-2011, 08:32 PM   #6
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Default Re: Dell 2407WFPb Monitor - Bad Cap

We normally ask new people to post clear focused pictures (please do - see my sig file below for instructions), but if your board looks like this one (another Dell 2407 thread)

http://www.badcaps.net/forum/attachm...6&d=1305906535

only the right side is "crowded". You can install the cap "leaning" to the left side and there is no problem. So you can get the 20mm diameter or larger with the "proper" 450V rating.

Last edited by retiredcaps; 06-04-2011 at 08:37 PM..
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Old 06-04-2011, 10:32 PM   #7
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Default Re: Dell 2407WFPb Monitor - Bad Cap

That is almost exactly what my board looks like.

Here is a photo of my board:
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Old 06-04-2011, 11:08 PM   #8
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Default Re: Dell 2407WFPb Monitor - Bad Cap

You didn't mention how you determined that that particular cap has failed.
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Old 06-04-2011, 11:34 PM   #9
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Default Re: Dell 2407WFPb Monitor - Bad Cap

What is the height of the heatsinks? (mm)
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Old 06-05-2011, 12:30 AM   #10
thewzard
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Default Re: Dell 2407WFPb Monitor - Bad Cap

Toasty: The height of the tallest heatsink is 20mm. The height of the bad cap is 45mm.

smason: See pic below.


EDIT: Misunderstood Toasty's question.

Last edited by thewzard; 06-05-2011 at 12:33 AM..
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Old 06-05-2011, 12:53 AM   #11
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Default Re: Dell 2407WFPb Monitor - Bad Cap

The white block of foam on the transformer, is it higher than the heatsinks?

-AND-

Is the metal cover resting on that foam and at the same level over the area where that cap is.

If yes - you can fit a 22mm diameter cap

If no - you can fit a 20mm diameter cap
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Old 06-05-2011, 01:23 AM   #12
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Default Re: Dell 2407WFPb Monitor - Bad Cap

Yes the white block of foam is higher than the heatsinks.

So far I have narrowed the selection down to these three capacitors:

20mm Nichicon
http://search.digikey.com/scripts/Dk...2W121MESY45-ND

22mm Panasonic
http://search.digikey.com/scripts/Dk...name=P11670-ND

and

22mm Panasonic
http://search.digikey.com/scripts/Dk...name=P10157-ND

I'm thinking of buying one of the Panasonic capacitors and the Nichicon capacitor as a backup just in case. I'm not sure which of the two Panasonics to get. Any recommendations?
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Old 06-05-2011, 01:50 AM   #13
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Default Re: Dell 2407WFPb Monitor - Bad Cap

Elite's PW series shows this cap as 740mA of ripple. Any cap you choose should meet or exceed that spec.

Nichicon is out of stock.

2nd Panasonic is below ripple spec.

The winner is the 1st Panasonic at 1.02A ripple (1020mA)

http://search.digikey.com/scripts/Dk...name=P11670-ND

Cut the leads off the old cap in place as close to the body as you can get. Remove it and clean off the caulk from the board. Mount the new one with some silicone caulk and a quick solder and you're done.

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Old 06-05-2011, 09:20 AM   #14
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Default Re: Dell 2407WFPb Monitor - Bad Cap

Unusual to see the large cap fail like that. On the other hand, if the 9 smaller caps on the power board are also the Elite brand, then you might want to replace them. Also, replace the 3 caps the the TDK inverter board, since the caps they use are of poor quality. I know it sounds like a lot, but since you already have the monitor open.....
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Old 06-05-2011, 10:32 AM   #15
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Default Re: Dell 2407WFPb Monitor - Bad Cap

Put the Elite PW series on the "Always Replace" list.
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Old 06-05-2011, 02:27 PM   #16
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Default Re: Dell 2407WFPb Monitor - Bad Cap

Whoa...okay. This is my first time at this so I'm going to need some help understanding some of the jargon. I googled TDK inverter board and a ton of stuff come up but nothing that looked like anything on the circuit I'm working on.

jetadm123: What is the TDK inverter board and how do I find it?

toasty: I would never have thought about looking at the ripple spec. So in short, now I know that when replacing a capacitor I need to look at the volts, uf rating, temperature, diameter, height, and the ripple specs. Are there any other specs I should be looking at when replacing a capacitor? Also, how did you know where to look for the ripple spec of the old cap? There are so many different ones.

Finally, when removing the caulk from the board, do I run the risk that I will damage the board? How would you recommend I go about that?

In summary:
1) Order P11670-ND - check
2) Replace other elite capacitors -- I'll try to find the correct specs first.
3) Replace the three caps on the TDK inverter board -- waiting on word from jetadm123.

Thanks for all of the help guys, I don't think I would have been able to do it correctly otherwise.
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Old 06-05-2011, 02:28 PM   #17
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Default Re: Dell 2407WFPb Monitor - Bad Cap

I think I found the TDK inverter board. Its the only board with three caps on it that says TDK LOL.

Anyway those are Taicon caps. Replace those as well?
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Old 06-05-2011, 03:55 PM   #18
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Default Re: Dell 2407WFPb Monitor - Bad Cap

>>Also, how did you know where to look for the ripple spec of the old cap?<<
Datasheets.

Start here: http://capacitor.web.fc2.com/

Which directs you to here: http://chinsan.co.th/index.asp

Which will get you to this: http://chinsan.co.th/files/PW.pdf

>>Finally, when removing the caulk from the board, do I run the risk that I will damage the board? How would you recommend I go about that?<<

Personally, I use a chainsaw...



Any plastic tool will work fine. Most of it you can peel by hand.
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Old 06-05-2011, 04:48 PM   #19
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Default Re: Dell 2407WFPb Monitor - Bad Cap

I'm having trouble on Elite's site. Maybe its my browser, I'm using IE9 and/or Mozilla Firefox 4. However, I was able to snag up a little bit of information.

These are the different series that they carry:
SM . PS . PF . PW . LM . LS. LF . LL . EM . ES . EL .EB . ED . EJ . EG . SS . SS-H . SB . SB-H . ND. ND-H . BP . LB . LB-H

How did you know to look for the PW series?
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Old 06-05-2011, 05:09 PM   #20
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Default Re: Dell 2407WFPb Monitor - Bad Cap

Says so on the side of the cap pics posted....
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