Flipped the power switch on my psu and spark on mobo

[Drew]

The previous psu in this system was a 400w HEC-400AD-TF
It was replaced by a 350w antec smartpower 350 (still smells like something burned in it)

Intern-

I was working on a server box with the super p4sce mobo in it (I don't know how old the machine is). The only thing missing from the box was a power supply (the previous one was dead). I had a spare antec smart power 350w psu lying around so I popped that in the machine and hooked everything up. Checked to see if everything was secure and once I had done that I turned the switch on the psu on. Nothing happenend, no light on the mobo or anywhere for that matter. Just a high pitch whining type noise coming from the psu along with a burning smell almost like that of a hair dryer. I shut the psu down and unplugged it then let it sit there for about 5 mins and then hooked it up and turned it back on again this time the fans moved a little bit but still no light to be seen anywhere. I figured I would just let the psu sit on for a little bit since the mobo hadn't been hooked to power for quite some time. After about 45 minutes later (was working on another machine) I asked my boss if I should take out the four pin connector since there was already a 24 pin connector hooked up to the mobo. Had a mix up in communication and I thought he said yes take it out. Anyway I hooked the psu back up and fired up the machine, the fans started up and whipped a ton of dust up and then there was a spark at the bottom of one of the capacitors by the back panel near the RAM. The spark was accompanied by a loud crack that sounded like a firecracker. I flipped the switch on the psu and unplugged it immediately. It already smell like something had burned but there were no marks on the top of the mobo or on the capacitor. There is no bulging or leaking and the capacitor is still in contact with the mobo from what i can see. The only thing that happens now when i turn on the psu is that high pitched whine. The same as when i turned the psu on the first time. So here are the questions that I have:

(I have not unhooked anything from the psu during any of these times i turned it on)

Could some of the dust stirred up by the fans have caused the spark and if so how did the dust cause it?

Did unplugging the 4 pin connector cause the spark and if how could that cause a spark?

If you have any suggestions/theories for the cause of this it would be greatly appreciated. I am quite perplexed for the reason that this has happened and any help at all is welcome. Thanks in advance

[Toasty]

Re: Flipped the power switch on my psu and spark on mobo

Dozens of threads on here about Smart Powers. They can be motherboard killers. If you're lucky, it didn't.

First thing I would do is obtain a working supply from another system if possible to make sure the mobo wasn't killed.

Then, open up the PSU and you'll find the noisemakers in there. Likely you're 5vsb is dead since no mobo light. Antecs SP's are -loaded- with bad caps.

Search for other threads on here with:
"antec smartpower" - 76 hits
"antec smart power" - 29 hits

When you get it open, use the other threads as a guide to get some pictures up so we can better help you.

Toast

[shovenose]

Re: Flipped the power switch on my psu and spark on mobo

3 things:
1. The antec smartpower has a deisgn flaw (internal bad capacitor failings)
2. Dont use a mobo without the 4pin power connector for the cpu
3. Maybe the old psu was ok an the mobis shot?

[Drew]

Re: Flipped the power switch on my psu and spark on mobo

I can't quite recall if I did this or not but I think I tested the old psu on a spare hd and it didn't work. Even if I didn't do that my boss told me that he was certain the system worked before he brought it in to work.

[Drew]

Re: Flipped the power switch on my psu and spark on mobo

This just came to me but since the mobo is in a server box would I need a psu that has a higher wattage than what is listed in the manual to power everything in the case?

Edit: Also in regards to shovenose. Would the fact that I didn't have the four pin power connector in have caused the spark?

[retiredcaps]

Re: Flipped the power switch on my psu and spark on mobo

The only thing that happens now when i turn on the psu is that high pitched whine.

I just ran across one of these power supplies with the same high pitched whine. It had 2 bloated 1000uF 10V and one, I believe, 22uF 50V (on the hot side).

With the bad caps, I was getting +11V DC on the 5V standby pin. The motherboard won't post now probably due to the high voltage on the standby rail.

I swapped out the 3 bad caps and now the power supply has no high pitched whine and the 5V standby measures a steady 5V DC.

Sorry, the power supply is re-installed and put back inside the case so I don't have pictures.

edit: The 22uF 50V was the root cause of the high pitched whine.

[Drew]

Re: Flipped the power switch on my psu and spark on mobo

So is it most likely the psu that caused the spark then and are they anyways to test if that it is indeed the power supply that caused it. Aswell should I still attempt to see if the mobo still works with another psu or is there a chance that that psu will get damaged? Silly questions I know but I rather be cautious and I don't have much experience currently.

[seanc]

Re: Flipped the power switch on my psu and spark on mobo

As previously mentioned, Antec Smartpowers are riddled with capacitor problems and must be checked whenever they are encountered.
Chances are, if you saw a spark from the motherboard, it's now dead. There's a remote chance it can be repaired.

I would get a known good power supply, i.e brand new - I'd use an Antec Earthwatts 380 and test.

[Drew]

Re: Flipped the power switch on my psu and spark on mobo

The chances of getting a brand new psu is pretty slim, these machines are just so i can get some experience. I do, however, have another 350w psu that I just pulled out of a machine that I know works. I am not really trying to get it repaired at this moment. I am more just trying to find out what works and how this occured. I will most likely have some more info on the status of the psu tommorow but other than that I can only try and answer inquiries and attempt to do troubleshooting steps and suggestions that people say.

[Toasty]

Re: Flipped the power switch on my psu and spark on mobo

The 4 pin is required for CPU power. Not having it in, the system should have failed to boot or some beeping from the BIOS screen. I've never been daring enough to not have it connected, but when it happened accidentally, the system simply didn't boot.

If you pulled it while the PSU was even -plugged in- and not discharged, you might have toasted the mobo.
PSU disconnected from wall -> push front power switch -> lights may or may not flash briefly or fans may spin a bit -> PSU is discharged.
You can now unplug cables, or swap cards, memory, etc.

If you unplugged it with the PSU on, it might be bin time...

Toast

PS: Decent, new PSU's can be had for relatively cheap. Stay away from all the glittery new ones with the excess cables, plugs, etc. A simple, solid, 450w+ unit @ <$30 is only some Googling away. I'm sure they'll be some recommendations from the membership on here shortly.

Oh, BTW, where are you located? Earth, I'm fairly certain, but could you fill in the location in your profile so at least we know which continent?

PPS: Welcome to the forums!

[Drew]

Re: Flipped the power switch on my psu and spark on mobo

I followed those steps and then worked on another machine until my boss was out of a meeting (about 45 mins) then I asked him about the 4 pin connector and there was a mix up in communication. He thought I said I had it out should I plug it in and he said if you have it out plug it in and see if that works. I said I had a 24 pin connector in so does that mean I should unplug the 4 pin connector and I thought he said yea unplug it see if that works.

Which leaves me wondering what the heck happened because it was the 3rd time i tried turning it on and the fans started whipping around and a ton of dust was blown around so I'm not sure what really caused the spark since if it was a psu issue then why did it not happen when the 4 pin connector was in. Then the issue of the 4 pin connector not being plugged in and the spark occuring during the time that it was out makes it seem like that was the cause. but then there was a ton of dust being blown about so I'm not sure if that could of had something to do with it. Gah, would just love to figure out what happened so I can put it behind me lol.

[seanc]

Re: Flipped the power switch on my psu and spark on mobo

If you were hearing a whining noise, I can 99% assure you the power supply had a bad capacitor.
That bad capacitor could have caused a voltage to go above its usual voltage, as mentioned by retiredcaps.

[Drew]

Re: Flipped the power switch on my psu and spark on mobo

Haha thanks and I just filled it in. On the note of the power supply I am interning at the moment so I really am not able to get another psu personally. I have another server box similar to the one that I am having the issue with so depending on the state of the psu that may have caused the spark there might be an option in getting a new one.

[shovenose]

Re: Flipped the power switch on my psu and spark on mobo

The abcense of the 4pin connector shouldnt causeanything to blow up. The system should just have spinning fans but no video, beeps or anyrhing.
Yes you need. The 4pin no mattdr if the mobo has a 20 or 24 pin connector. Try thr system wih a different known good psu and see if it works.

[Topcat]

Re: Flipped the power switch on my psu and spark on mobo

I've fired MANY systems with the 4 pin plug out, never hurt anything....the system just wouldn't POST. Always shut the power off, plugged the 4 pin connector in, and fired it up.......never had one fry because the 4 pin connector was left unplugged.... Who dreamed that one up>?!?

[Drew]

Re: Flipped the power switch on my psu and spark on mobo

If you were hearing a whining noise, I can 99% assure you the power supply had a bad capacitor.
That bad capacitor could have caused a voltage to go above its usual voltage, as mentioned by retiredcaps.

I kind of figured something was amiss with it but wasn't sure what the issue was. I looked around a bit on google to see what could cause it and there were a bunch of places saying that the smartpower series was very unreliable. Being an intern and all and not having hardly any experience figured since my boss didn't tell me that anything was wrong with it that it would be fine but looks like that wasn't the case. My only question is why didn't it occur any of the times I had the machine on before, especially when I had it running for 5 minutes straight?

[seanc]

Re: Flipped the power switch on my psu and spark on mobo

the power supply I am interning at the moment....

What does 'interning' mean in this context?
I'm not familiar with the word intern, outside of someone working in a temporary position to gain experience.

[seanc]

Re: Flipped the power switch on my psu and spark on mobo

My only question is why didn't it occur any of the times I had the machine on before, especially when I had it running for 5 minutes straight?

Perhaps in the last off/on cycle before it blew, the capacitor in question failed completely, causing a short.

[Drew]

Re: Flipped the power switch on my psu and spark on mobo

Just hooked up one of the working psu's I had in another machine and a light came on. Should I hook everything up to the working psu and see if it boots or just hook it up to a hd first?

[Toasty]

Re: Flipped the power switch on my psu and spark on mobo

... My only question is why didn't it occur any of the times I had the machine on before, especially when I had it running for 5 minutes straight?

My car started this morning when I went to work. Now I want to go home and it won't....

doo-doo happens!