I've repaired no less than 2 dozen MOBOs of varying brands (Soyo, MSI, Tyan, Dell, etc.) that all were simply in need of a capacitor or 6. Never bothered with a kit, just grabbed some from the 'Shack or the junk drawer or tacked onto an order to Digi-Key or Mouser. Easiest way to diagnose a bad electrolytic is a bulge on the top of the caps, or in the worst case fluid on or around it. Most are usually in the power section (usually have a toroid bearby) but some were in varying locations causing the odd behaviors you mention.
Saved my tail on a MOBO based RAID situation where I'd have most likely lost it all if I couldn't have gotten the board up again. They really aren't hard to replace, get the same MFD value and a voltage rating equal to or higher than the original (hopefully it didn't get too hot and melt the wrapper) and just like any soldering on a multi-layer board that has SMT components nearby, use the finest tip you have and medium heat for minimum time. If it's a dead board then the couple bucks are a no brainer. If you have a decent multi-meter with capacitance metering, remove the suspect unit(s) and check to see if they're ok or not. Got nothing to loose at that stage. Good subject to bring up. Curbside finds are prominent around me because no one wants to wait for the biannual county electronics recycling drive to come around so they set them at the curb and usually someone like me comes along and snags them. $5 in caps can make for a nice Christmas gift to a digitally challenged relative :) HTH - as always YMMV :) Greg www.distinctperspectives.com -----Original Message----- From: Kent A. Reed [mailto:[email protected]] Sent: Sunday, December 28, 2008 12:14 AM To: [email protected] Subject: [Emc-users] Bad motherboard capacitors? Gentle persons: In part because of the need for a parallel port and in part because of the latency-inducing problems that seem to arise more often with recent chipsets, we EMC'ers often seek out older motherboards/cpus. I'm curious to know if anyone has run into the problem of bad capacitors on their older boards, in particular, with Nichicon capacitors. (see, for example, http://en.wikipedia.org/wiki/Capacitor_plague or http://news.cnet.com/PCs-plagued-by-bad-capacitors/2100-1041_3-5942647.html) If bad caps always left the system as dead as a Norwegian Blue parrot, then they'd be easy to diagnose. Unfortunately, it is also possible for them to result in various headscratchingly odd behaviors in systems that seem as if they ought to be working, which is tough to diagnose. This problem is by no means found only with Dell Optiplex systems of a certain age, but Dell sold or leased so many to businesses that they're statistically the most likely brand to be bitched about. I know several on this list have mentioned their success with Dell Optiplex GX/SX 260/270/280 boxes coming off lease. These are great little machines, especially the SX boxes which I personally like on several counts, but I have found I have to be cautious buying them sight unseen. Sometimes machines that failed in service were recapped in the repair facility, more often the motherboard or the whole machine was simply replaced. Good or bad, many of these boards and machines have made their way inevitably to eBay and surplus-equipment channels. Let the buyer beware. Ask if the seller doesn't mention that motherboard capacitors are new, replaced, recapped, or somesuch. "Refurbished" may be an insufficient description since it could just mean they erased the disk drive and wiped the finger munge off the front panel. Fortunately, there is at least one enterprising person on the internet who sells capacitor sets for motherboards but you need a certain level of skill to do the job. Regards, Kent PS - if you've ever tried to bring vintage tube-type electronic gear back to life then you already know all about the need to replace electrolytic capacitors but you might not have expected digital computers newer than your car to have the same problem. ---------------------------------------------------------------------------- -- _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
