Well i’m building my first PC and so far everything was going fine.
I got the parts yesterday and realized that the case didn’t come with any standoffs and screws for the motherboard. No problem, I’ll just get them tomorrow I said. Just to see if everything is working, i sat the motherboard on the box it came in and connected the power supply.
With the power supply connected to the board with ram and processor only, it fired up and started going into bios on the monitor. I turned it off and went to bed.
Well I got the standoffs and screws today. Installed them in the case and screwed my motherboard in properly. Connected all the fans, hard drive, dvd drive, usb ports etc. Turned it on, and received a loud “POP” from the psu with a spark and smell of smoke.
Any ideas? Faulty psu? I’m returning it and gonna try again with a replacement.
The loads were:
Intel I5 2500k processor
1 motherboard
1 Sata hdd
1 dvd drive
2 usb ports
8 gb ddr3 ram
3 case fans
No video card at the time
The power supply is a coolermaster 460watt psu. Think it was underpowered, faulty, or installation error? Think the motherboard got fried along with the PSU? There aren’t any burnt spots or solder joints for what ever that’s worth.
Cases have many standoff positions depending on motherboard form, but not all of them should be used. So make sure that the standoffs you have screwed on the case correspond to the holes in the motherboard. If you have a standoff at a place that there’s no hole in the motherboard it might be shorting something on the underside.
even if you had a shorted standoff behind the motherboard. any decent power supply should have over-current protection (OCP) and just turn off if any of its power rails are shorted to ground. if the power supply went bang then something was wrong with it.
Yeah the PSU has all kinds of over voltage and under voltage protections. That’s a relief that nothing was done wrong. And yeah I made sure to only use the standoffs where needed.
So if the PSU was faulty, any chance it fried my board?
Are you positive you did not mix up two cable connections. Last time I did this there were two power cables that would fit in two places. Maybe you put them in the right place the first time and not the second. ijs
The above makes more sense to me than a simple overload. It had no time to overload. It has fuses and protection for that.
You’re right but since all connectors are keyed and cannot be accidentally misplaced, a shorted standoff (or a short in general) was the only user error I could think of.
Since user error is out of the way, the only reasonable explanation is that it was simply a bad PSU. The popping noise was probably a bad capacitor, this can happen even in the best PSUs.
Assuming that the pop happened as soon as it came on, I doubt it was an underpower issue, especially with no video card. You should not have had that much of a current draw until the drives and fans are up to speed. If it were an undervoltage, most likely it just wouldn’t turn on or would reboot.
If you shorted out the board (and I did this once early in my career) the failure would occur on the mobo and not the PSU. My guess is a bad PSU. Either something got in there overnight and shorted it out or you blew a capacitor. Unfortunately you’re not in the position where you can try SCE to Aux.
Well I picked up a new psu today and reinstalled everything. It all went perfectly, in fact, I’m typing this message on the very same computer right now.
It seems like it was just a faulty power supply. Thanks for all the help guys.
On some old pre ATX PSU, the main power cable to the MB was split in two pieces and semi-keyed, ie you couldn’t put the cable 180[sup]o[/sup] rotated, but you could put the first cable in the second position and the second one in the first position.
The correct installation was so the black wires from each cable were side by side. If it was reversed supposedly it would fry the MB but I never tested it.
As an electronic hobbyist, what probably failed in your power supply was a switching transistor (or two, depending on the design, some also use a switching regulator IC for the standby output); that is usually the cause of failure when it happens immediately after turn-on and sparks are also observed (even in a good power supply a transient overstress on a power transistor during a short or overload can cause it to fail, especially if it is marginally rated). On the other hand, if it happened after a few seconds and a big cloud of white smoke came out, then an electrolytic capacitor blew. Although, such capacitor failure usually means that something serious occurred (such as overvoltage, more gradual failure results in a much quieter pop and little if any smoke). This is all based on experience, including with making my own power supplies (switch mode power supplies).
A few weeks ago my father was replacing the RAM in his machine. The machine wouldn’t boot up, so he put the original sticks back in–then it wouldn’t even power up. I had him bring it here, swapped out the PSU with an extra I had and everything worked fine. Not only did the replacement reboot without a problem, my PSU tester verified it wasn’t putting anything out. There was no accessible fuse or other reset switch.
It could easily be a coincidence that the PSU went right as he was monkeying with the insides, but no, that’s a bit over the top. Can anyone speculate on the mechanism that could have fried the PSU?