Replacement refurb board blew caps instantly.

[misterT]

Hi all,

I have a Dell motherboard that has the capacitor plague and 12 caps have obvious signs of failure. The majority of failed caps are the infamous Nichicon variety with a date code: HN0249 (1800uF, 6.3v). Initial symptoms were a couple of thermal event errors followed by the system not booting at all.

I bought a refurbished board (supposedly refurbed by Dell) and noticed that it had the exact same caps as the old board, but since it had a warranty, I thought I'd install it and see what happened. Well, two caps blew immediately on the first boot attempt.

I pulled the PSU and bench tested it with a multimeter and the voltages all were well within tolerances of the pinout schematic. Of course, this was not under load. I can't find an easy way to open the PSU to check for any blown caps inside.

All fans are functioning, although I could not do an RPM test. The case is spotless, in terms of dust and dirt. I re-installed the processor using a good quality thermal paste. Since the refurb blew out so quickly, is it reasonable to suspect something other than bad Nichicons is to blame?

Any insight would be greatly appreciated.

Mario T

[Per Hansson]

Re: Replacement refurb board blew caps instantly.

Was the datecode on the new boards caps the same?
Did Dell do a boo-boo and install them backwards (if it's a refurb...)

[Toasty]

Re: Replacement refurb board blew caps instantly.

Could be an identical but (old) new board from the same date range.

2 possibilities I see:
- Caps were DOA (because they were from the bad dates) and powering them made them blow
- Caps are old and needed to be "re-formed" by applying ever increasing voltage over a few hours. Full power and a lack of oxide layer just made them short out.

Recap it and you should be okay.

Pics of the PSU case plz, if you can't figure how to open.

Toast

[misterT]

Re: Replacement refurb board blew caps instantly.

Thanks for the replies.

The date codes on the refurb were identical to that as my original. The polarity has not been reversed.

Toasty: I'm not really sure how I would go about re-forming the caps. Is that via software or hardware?

This link: http://images04.olx.in/ui/2/63/29/34675429_1.jpg is the power supply that is on the 650, and I can get the plastic shroud off the front, but the sides don't want to budge. I don't want to cavemen them off.

Thanks again,

Mario

[Toasty]

Re: Replacement refurb board blew caps instantly.

Reforming is a process of applying voltage slowly and in steps to the board/caps. Requires a variable voltage bench power supply.

I think the plastic casing slides off, but I do not have any experience with these. Then you remove the screws. See if you can find a picture of one to see how it attaches. I saw one on Amazon without the plastic casing.

http://www.amazon.com/Genuine-Dell-S.../dp/B002WZZ2TK

[Per Hansson]

Re: Replacement refurb board blew caps instantly.

You write it had a warranty...
Can't you just ask for a new board then?

[misterT]

Re: Replacement refurb board blew caps instantly.

Per Hansson: Yes, I've already returned the refurb. This thread is more for when I either recap my original board, or get another refurb, so I don't keep blowing caps.

Toasty: I did end up getting the case open on the PSU. It slid off with some force...more like a quick rap of my fist. Although there are a few larger Nichicons in there, they appear to be in good working order.

[Per Hansson]

Re: Replacement refurb board blew caps instantly.

Ok, the recapping tutorials here on Badcaps will help you (Look in the FAQ section)
Also of course Top Cat who owns this site offers a recapping service, if you don't feel inclined to do it yourself

If you search for your Dell's model name (and deviates) here on the site you will likely find examples that people have already recapped, might be of help aswell...

[Toasty]

Re: Replacement refurb board blew caps instantly.

Appearances are deceiving. What is the series and date code on the PSU caps? Are they all Nichicons?

[misterT]

Re: Replacement refurb board blew caps instantly.

Thanks Per Hansson. I've been perusing the tut's and other posts on Badcaps for the last couple of weeks. I'll probably end up going the recap route rather than hoping I find a refurb that has had the caps replaced. Thanks also for the recommendation of TopCat's services.

Toasty: Thanks, the Nichicons that I can see are H0251 H0248, so yes, they are on the dud hit list.

There are a couple of LTecs and a couple of Rubycons in there as well.

[Toasty]

Re: Replacement refurb board blew caps instantly.

Well, if the Rubys are small ones, they're okay. Ltec & Nichicon have to go. If you can post a few shots of the insides too, that would be great.

[misterT]

Re: Replacement refurb board blew caps instantly.

Here's a pic of my original motherboard with a bank of blown Nichi's as well as the inside of the PSU (there's a Ruby just below the heat sink lower right and one at the very back by the vent):

[Toasty]

Re: Replacement refurb board blew caps instantly.

The Nichicon PW's are a one-for-one direct swap. Still in production. Were not in the bad caps series that I recall seeing. It's just that there were some Nichicon series that were crappy from that time frame, up until late 2005. It's really your call to replace them or not. Do replace the Ltecs. Use PW's for those replacements too.

Of course, you can always kick it up a notch and go with Panasonic FM's.

The NCC/UCC KY's are fine and the Ruby YXG are probably fine too.

[PCBONEZ]

Re: Replacement refurb board blew caps instantly.

the Nichicons that I can see are H0251 H0248, so yes, they are on the dud hit list.

Only the HN and HM series caps [in the date range] are on the 'dud list'.
A PSU with HM or HN would be unusual.

[misterT]

Re: Replacement refurb board blew caps instantly.

Thanks for the information, Toasty.

Thanks, Bonez. I was thinking it was the dates and the brand more than the series. Thanks for the clarification.

[PCBONEZ]

Re: Replacement refurb board blew caps instantly.

No worries.
There is a lot of info to digest when you first get into caps issues.