Saving a Motherboard from Capacitor Plague

I assembled my office desktop using a Tyan S2895A2NRF (aka K8WE Thunder) motherboard in 2006. In terms of features and performance, it is still an outstanding workstation motherboard. The dual Opteron 275s with Alpha PAL8150 heatsinks run cooler and faster than 2009 Xeons. I get better SATA bandwidth with 1TB Seagate disks than on DL160G5 servers.

In terms of component quality, however, Tyan got unlucky. Yes, capacitor plague is real. In mid-2011, one day I had to reboot my desktop. The motherboard never got into POST. I jabbed the power button, thinking I had shut down instead of restarted. The fans spun for four seconds, then it was lights out. This happened every time I jabbed the power button.

In contemporary culture, the normal reaction would be to order a new PC. The S2895 uses 400MHz DDR RAM, and the Opeterons and heatsinks are Socket 940 vintage, so it is hard to reuse anything except the cabinet, disks and power supply.

The only way to reuse everything else was to try to find a replacement motherboard that is either the S2895 again (very likely with more bad caps) or a close match. So I sent a couple of emails to IIT's rate contract vendors, asking if they can locate one among a small list of ancient motherboards. One of them had supplied my original motherboard. I also asked an outside vendor.

Then I started reading more about capacitor plague on the Web. Armed with a magnifier, I found the clues: five caps with their tops bulging and one that was rising up from the PCB. I also found, which ships high-quality (low ESR) caps worldwide. I ordered 5USD worth of replacement caps (with some extras) and shipping was 1.37USD.

Digression: I know the rate contract vendors are not under any agreement to supply items not on rate contract. Nevertheless, interacting with them can be a drag. They do not reply to email, need several reminders for small items, and need dozens of telephone reminders for big items ("are you sure you need it"?) before they respond, if ever.

The message is clear: they are after crores worth of purchases and cannot be bothered by your piddling 50,000INR worth of business. So I was overcome with gratitude on finding I could not believe that just by clicking a few links and typing in my PayPal ID, I could get caps shipped all the way to India.

Like Dobby, I almost broke down weeping when I realized that there are nice people across the world that would actually want to do business with me. Insignificant lowly me. Imagine! Eventually, only the outside vendor replied, quoting 30,000INR (about 800USD) for an approximate replacement.

The new caps arrived within a week; fortunately India Customs was after bigger game while my caps snuck into the country. I have had an IBM R32 inverter and some other small items stuck in Customs for ever and lost, so this was lucky.

The nice part about this adventure was that I could keep reminding myself: "What do I have to lose? I was going to toss that motherboard anyway." I heated the PCB pads and pulled out the legs by successive iterations in about 4 passes over each cap. I used a 35W iron which is more power than needed. If you are experienced in soldering and desoldering, you know that a high wattage iron touched to the pads very briefly is better than a low wattage iron touched for longer.

After the caps were out, I used a hypodermic steel needle to clean up the holes. So that was three heating cycles per pad. The fourth and last heating cycle was used to solder the new caps on. It is important to heat the PCB vias well and use gravity to let the solder flow into the hole.

Clear swelling of the old cap. Lucky no leaks yet.

All the pulled teeth on exhibit, all swollen at the top, one with the rubber base being pushed out.

An old (not yet dead) "KZG" cap neighboring a new Rubycon MCZ cap.

Old (brown) and new (black) caps. Hopefully the surviving brown ones won't blow tomorrow!

So I finished up and clipped the excess leads, reconnected the power supply, and ... bingo! the board powered up as if it had no hint of the lobotomy in between! Yoohoo!

I have no idea how long it will last, as other caps may go bad, or other non-cap parts may have been damaged already. But even if it takes me to the end of 2011, at 6.37USD for a board that would take 800USD to replace, that's not bad at all. The whole job, including ordering the caps, took me under two hours. Luckily, I am not so busy and successful that I cannot afford two hours of repair time after using a motherboard for five years.

A problem was identified, caps were ordered from the USA and delivered in India, suspected caps were removed and new caps installed, and the unit restored to health, all before local motherboard vendors could so much as reply to an email inquiry. Why are Indians too busy to get any work done?

PS: Thanks to Sasidhar for some of the photos.

Update: Made it to the end of 2012!

Update: Made it to the end of 2013!

Obituary: Made it to the end of 2016! Died a few days into 2017. Would not power up at all. No visible bad caps. The board lasted from summer 2006 to the end of 2016, over ten years, with the above repairs made in mid-2011.