USB Shortcircuit?

D

Dmitry S

Geek Trainee
Hello people,

I have a bit of a problem, and i'll make the story as short as possible, so bear with me here if you can...

OK, so i was lengthening a USB cable for a project of mine and the only time in my life that i don't double-check to see if the cable i'm working with is attached (and i do this quite often) to my PC something has to happen.

So, i had stripped off the plastic insulator, the shield cover and wires from the cable and was about to wire the power wire to the other power wire, when it happened to cross the TX, or the RX wire (i'm pretty sure, as the ground would harmlessly eat up the current through the power wire, but i could be wrong, not my field) and all of the sudden, my computer makes a beeping noise similar to an EKG machine flatlining (exact sound actually)
My younger sister was sitting nearby and reported a smell of some kind, but thats not uncommon with my computer as its quite the dinosaur.

My system locks up, mouse and other input unresponsive, and i shut her off.
Around 20 sec later, i power her back up, and i get no video output, not sure about the POST beep. Eventually, my system manages to boot successfully into windows, and i resume what i'm doing. Right then it locks up again, and after i try to reboot, i get the same thing again. NO video, NO POST beep, and no clicks (i think at least). The fans work and everything, and the power lights work as well.

One other thing, when i flip the power switch in the back of the supply, i notice the power light flicks on for an instant when i flip it to ON, and when i flip it to OFF, it does it again, except the fans in my case suddenly lurch a bit, as in they spin for about 1/2 revolution and just stop. Almost as if my computer turns on for a split second. Weird? Well, i've never noticed it before, and i don't think thats normal.

If anyone can help, i would appreciate any advice offered. I believe this could be a power supply problem (the motherboard could also be damaged i'm thinking, but power supplies are cheaper to fix, so i'll try it first i suppose)

I will do a follow up post with all of my specs and additional information i notice.
 
Dmitry said:
I believe this could be a power supply problem (the motherboard could also be damaged i'm thinking, but power supplies are cheaper to fix, so i'll try it first i suppose)
Click to expand...
yeah, i agree it does sound like your PSU output has reduced to the point of not booting, it's probably just a coincidence that this happened at the same time as you were messing with the USB cable
 
I should be able to grab a new PSU today, so I'll install it and see what happens.

BTW, my PSU is rated at 340W peak, and i have a 2.4P4(a - i think) on an older MSI motherboard (computer wont work at home, so i've no way to be sure, I'll have to write it down) with 1024mb of DDR333 RAM. I also have an Nvidia Geforce FX 5700 Ultra with a 12v supplemental power connector. My power supply has worked fine up this date and power demand has not been exceeded with 2 CD/DVD drives, 2HDDs a additional USB 2.0 hub in a PCI expansion slot (not a PCI card though, just in the rear of the expansion area) and a telephone modem) I also have 3 additional fans to provide additional airflow as my case is nearly seven years old and not very breathable.

Now remember, this happened when i crossed two wires from an exposed USB cable, the power wire and a receive wire (almost positive).

Also, i've done a little research, and a USB 2.0 line pumps up and around 500ma of pushing power, and i'm wondering if this is enough to upset a PSU. Something tells me this isnt a coincidence, but as suggested earlier, it very well could be. If anything, perhaps its time to upgrade, but i really just want to try counterstrike on my parabolic wi-fi reciever. I would love to have my old computer back, as its served me faithfully since 2002.
 
It could be nething... So lets start with Barebones Method..
Take out the Mobo from the Case..
leave it with only.
Processor,
1xRam Stick
1xHDD
1xVideo Card(Only if u dnt have an onboard)
Use Flat face screw driver to short Pins and start the computer...
 
well, i've officially tried everything now. I removed everything, RAM, all cards, devices, add-ons, you name it. Just a power supply and a CPU and the motherboard of course. Still no warning beep of any kind. I even removed the CMOS battery and let it sit for a good half hour until the capacitor drained and no dice. The one other thing i havent tried is removing the processor. My board should give a warning beep, even an auditory warning screaming "NO CPU INSTALLED" over and over. I've mysteriously burnt out a processor before, but lickily it was under warrenty, and actually replaced free of charge. I'll try that tomorrow anyway. Its late and i'm going to bed. Thanks guys, i'll continue my quest tomorrow, and try to scrounge up some freebie parts and money for any replacements i might need.

BTW, heres some images of my board for reference if anyones curious:


Heres the underneath: http://i172.photobucket.com/albums/w9/quicksilverut/BACKSIDE.jpg
Heres the topside: http://i172.photobucket.com/albums/w9/quicksilverut/FRONTSIDE.jpg

BTW, Karanislove, what do you mean short pin with a screwdriver? Something to do with jumpers on the motherboard? If you could clarify what you meant, that would be nice. Thanks for the help too.

CORRECTION, you meant shorting the pins that the power switch connects to right? Never thought of that, thats pretty spiffy. Quite the novel idea.
 
Dmitry said:
CORRECTION, you meant shorting the pins that the power switch connects to right?
Click to expand...
yeah, so you can remov the mobo from the case[ot]as the wires are usually attached[/ot]
 
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