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Supermicro / Ablecom SP302-1S Power Supply Failures

At my day job we're seeing some failures of Ablecom (Supermicro) SP302-1S power supplies. These SP302 units are used in 1u Supermicro servers. We had one failed one that was out of warranty, I decided to peel it open and see what went wrong.

Not surprisingly, a Teapo capacitor (1000uf @ 10v) was looking pretty bloated. Replacing it with a random pull that was laying around the lab fixed the power supply. More faulty Chinese capacitors. We've seen 4 more of these supplies fail at work, so my guess is all of them are suffering from the same issue. The other failed ones at work are under warranty, but I'm afraid the replacements will have the same faulty components.

Notes: Revision 3.1, Ablecom, SP302-1S used on Supermicro PDSMI+ system boards. Symptoms, units won't power on, LEDs blink faintly, repetitively, indefinitely. With working supply they come on, even with unit powered off.

(Blue electrolytic capacitor on edge of board is the replaced one.)

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Comments (18) Trackbacks (1)
  1. Thanks this fix saved me 100 bucks for a replacement = ) kudos

  2. Yup, we had one of these power supplies fail in April, another in June. Thankfully, we have no more to fail. As the second failure occurred just outside warranty, I may try replacing caps, myself.

  3. Yep – just replaced a cap in one of these units. Guess what? Same one. Just go with a good quality cap and step up to the next higher voltage in class – i.e. go 1000uf/16V instead of 1000uf/10V. Guaranteed not to fail.

  4. Interesting stuff thanks. Had the same issue, same cap!

  5. Haile,

    Hello, i had 2 of these failed almost at the same time, thanks to this article i replace the same Cap. it works fine. now need to buy one since i took it from the other bad one. thank you

  6. Stumbled upon the very same problem, with the very same capacitor.
    Thanks a lot for this post, it saved me a lot of grief and downtime.

  7. Can’t believe I stumbled upon this thread searching for a new power supply. Bought a new capacitor at Radioshack for $1.78 and I’m back up and running. Many many thanks!

  8. Also found this post and fixed my PSU for a few dollars – many thanks!

  9. We’ve got lots of these boxes, and the PSUs have been failing recently at an alarming rate. I’ve just retrieved two from the recycle heap, and found exactly the same problem (same cap, top bulging and with a little hole in the middle. They’re being replaced at the moment.)

    Many thanks for the post!!!

  10. Thank You,
    Problem solved!

  11. Hey great information. I too came across this while trying to search for a second hand one. Seems that one will be the same, so it would have been a waste of money. I checked out the capacitor in question on my unit and it doesn’t look bulged in any way, but the symptoms are exactly the same, ticking noise in the power supply while connected to power and Led flashing opposite side and not power up. I’ll change it anyway as it can’t hurt, anly costing me $1. Thanks again.

  12. Same problem and solution here; thank you for this page!
    I had a bit of a hard time finding a 10v or 16v 1000µf capacitor that would fit–the one from my local electronic store is fatter than the green one you pulled.
    I went ahead & unsoldered the other green cap just to the left of the bad one as it looks like it is the exact same cap (mine had manuf. dates 2 months apart).

  13. Same problem, I tried your solution. My server is on now. Thanks a lot.

  14. For the life of me, I can not locate the LED that should be blinking in this burnt out capacitor scenario. Can anyone please point it out?

  15. You wouldn’t know where I might find a schematic for this power supply would you. We had one fail about 3 years ago (still trying to see if it got buried in a box so I can fix it). Another one failed last night, but the caps you meentioned are fine. Thought I would try to trouble shoot it and use it for an emergency spare.

    Thanks in advance.


    • If you locate a circuit diagram, I’d love to get a copy. My SP302-1S doesn’t go on and it may be the capacitor mentioned in this string or it may be that some of the power supply leads go to a switch. I’m using the PS separately from a server that it was designed to power. Thanks!

  16. Just wanted to add another data-point that our power supply died due to the exact same capacitor going bad. Went and got another 105C rated 1000uF cap but at 25WVDC.
    It was a little fatter than the original 10WVDC cap so we weren’t able to push it down flush to the PCB, but just left about 1/4″ of its leads showing and it still worked fine. FYI the original 10WVDC is 5/16″ diameter

  17. That was my problem as well. Replaced with 1000u 16V

    Thanks to all of you,

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