Fired Mobo by plugging in keyboard????

Hookster264 · 09-14-2009, 11:00 AM

I am upgrading a computer for my mother-in-law with a new mobo, cpu and ram, using her existing IDE optical and HDD. (these are to be updated soon too)

Mobo is EVGA nForce 730i.
CPU is Intel E7500 core 2 Duo
Ram is G.Skill 2x 1Mb GBNQ

I had the system powered on, all was working fine. The system was almost at POST and the display recognized the change in CPU and required CMOS updated to continue.

I went to plug a keyboard into the back and the system shut down. I thought I saw a small wisp of smoke coming from the back side; I also had the back side panel off.

Did I just fry the mobo? How could this happen by just plugging in a keyboard?

I did notice the mobo was a bit loose and slid maybe 1cm when plugging in the keyboard. Could the mobo have slid against a standoff and shorted?

Now when I attempt to power on the system all the fans will spin for a second, but it shuts off automatically right away.

Yamikotai · 09-14-2009, 11:25 AM

Yup, sounds like it shorted to me.

carnageX · 09-14-2009, 11:33 AM

Take the board out of the case and see if it powers on.

Hookster264 · 09-14-2009, 05:09 PM

Okay I removed the mobo, and consequently had to disconnect all power connections.

I placed mobo on my desk and just plugged power to mobo and cpu. It powered up fine.

I reinstalled mobo into case and connected power to mobo and cpu only. It powered up fine.

I connected power to optical and HDD. It would power then flicker off.

I disconnected the optical with HDD powered only. It powered up fine.

I switched power from HDD to optical. It powered up fine.

I reconnected both HDD and optical. It powered up fine.

I connected all fans; everything now connected. It powers up fine.

Wierd!

oldskool · 09-14-2009, 05:15 PM

Well that's good everything is powering up fine now, but as a rule, I will almost always plug in mice, keyboards, etc., when it's off just as a precaution.

Not to say I haven't plugged in things while it's powered up, but usually I don't. It comes from being a guitar player, which you would never plug things in while the amps on usually.

It sounds like you are ok, but just keep an eye on things just in case.

veedubfreak · 09-14-2009, 05:19 PM

USB keyboard? Wonder if the psu is too old/weak to power everything and plugging the keyboard in was that last bit of power needed to push it over the edge.

Or you could have a bad molex on the power supply or something was shorted and reconnecting everything fixed it.

Hookster264 · 09-14-2009, 05:46 PM

I did recommend she upgrade her psu originally, but she was on a budget and could only afford the mobo, cpu and ram right now. Her current psu is an Enermax 300W, 22Amp +12v.

Since she is not installing a gpu card and only using onboard video right now, this may just barely be enough. I will recommend to her that the psu be the next upgrade as soon as possible.

carnageX · 09-14-2009, 07:20 PM

Quote:

Originally Posted by oldskool

Well that's good everything is powering up fine now, but as a rule, I will almost always plug in mice, keyboards, etc., when it's off just as a precaution.

Not to say I haven't plugged in things while it's powered up, but usually I don't. It comes from being a guitar player, which you would never plug things in while the amps on usually.

It sounds like you are ok, but just keep an eye on things just in case.

Hotplugging USB items should be fine. I've done it with my USB mouse/keyboard multiple times in Windows.

Quote:

Originally Posted by veedubfreak

USB keyboard? Wonder if the psu is too old/weak to power everything and plugging the keyboard in was that last bit of power needed to push it over the edge.

Or you could have a bad molex on the power supply or something was shorted and reconnecting everything fixed it.

THat's kind of what I was thinking as well, that there's a bad power connector, or the PSU is weak, especially since it wouldn't power up when he had both the ODD and HDD hooked up at once.

c0rr0sive · 09-14-2009, 07:24 PM

Usualy when hot plugging a PS/2 item such as a keyboard/mouse, it will blow the PS/2 ports out, but the board it self will be fine, just use USB compatable keyboards and the such.

But hot-plugging a USB device, in MOST cases is ok, I have seen some odd things happen, such as a random, 1, out of like 3000 hotpluggings of a jumpdrive, fry the drive and USB controller.

Sounds as if you didn't secure the board like you should have, and it slid out of position and shorted onto a stand off, or as others though, maybe the psu is pushing it, as enermax psus, aren't really good psus.