URGENT: Computer doesnt turn on

adith_neo

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Aug 17, 2010
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Help ! yday i disconnected my hard drive and put in my frnds hard drive and installed XP. All of a sudden the computer switched off. and could never turn back on .

To trouble shoot, i removed one device by one, and found that there was a problem with the graphics adapter.
I've a Nvidia Gigabyte 8800 GT which was working flawlessly till yday.

The things i've done till now :

1. Removed the graphics card and attempted.

Result: Computer turns on
Which means there isnt a problem with the PCI e slot

2. Removed The 6 pin power supply to gfx card

REsult: Computer turns on

Windows gives a warning msg that the power supply isnt connected, which means the gfx card is indeed ok.

3. Plugged in the 6 pin power supply, i had a spare ( i tried using both)

Result: Computer doesnt switch on.

Please help me, I'm not in a position to get a new card too.
 

adith_neo

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The one was a seagate, and the new one was WD.

I removed my old one, plugged in the new one, installed XP,

removed the WD , and plugged back my SEAGATE

The Computer turned off suddenly during the installation process itself. Does it have anything to do with the hard drives ?
 

adith_neo

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have a 500W PSU, Some Indian Brand. It was working flawlessly till i switched hard drives. IT juts amazzes me how it happened all of a sudden ? is there any workaround ? or is there any steps i shud follow ?
 

adith_neo

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actually, its a 500 W zebronics. I said some Indian, cos u ppl wont be knowing abt these brands. It s made in china tho , like al other brands. Its probably in the mid range of PSUs.

Anyway one of my frnds suggested tat , the PSU wud ve flipped out when i inserted the new hard drive, cos it wud ve required more power. I think that could be a rational explanation to the problem . Any ideas to test the PSU myself ? without opening the case of course, cos i still have warranty on it !
 
I know from reading here that Zebronics is a common, inexpensive (by Indian standards) PSU available in India. But compared to what we like to recommend (Corsair, Antec, Seasonic, etc), it ranks about 2 steps above junk. It is nowhere near a mid-range brand.

Work through our standard checklist and troubleshooting thread:
http://www.tomshardware.com/forum/261145-31-read-posting-boot-problems
I mean work through, not just read over it.

Breadboard - that will eliminate any kind of case problem you might have.
http://www.tomshardware.com/forum/262730-31-breadboarding

The breadboarding thread has a paragraph about how to build and test a PC in stages.

Breadboard with just motherboard, CPU & HSF, case speaker, and PSU. You do have a case speaker installed, right? If not, you really, really need one.

You can turn on the PC by momentarily shorting the two pins that the case power switch goes to.

You should hear a series of long, single beeps indicating memory problems.
Silence indicates a problem with (in most likely order) the PSU, motherboard, or CPU.

If no beeps:
At this point, you can sort of check the PSU. Try to borrow a known good PSU. If you cannot do that, use a DMM to measure the voltages. Measure between the colored wires and either chassis ground or the black wires. Yellow wires should be 12 volts. Red wires: +5 volts, orange wires: +3.3 volts, blue wire : -12 volts, violet wire: 5 volts always on. Tolerances are +/- 5% except for the -12 volts which is +/- 10%.

The gray wire is really important. It should go from 0 to +5 volts when you turn the PSU on with the case switch. CPU needs this signal to boot.

You can turn on the PSU by completely disconnecting the PSU and using a paperclip or jumper wire to short the green wire to one of the neighboring black wires.
http://www.youtube.com/watch?v=5FWXgQSokF4&feature=youtube_gdata

This checks the PSU under no load conditions, so it is not completely reliable. But if
it can not pass this, it is dead. Then repeat the checks with the PSU plugged into the computer to put a load on the PSU.

If the system beeps:
If it looks like the PSU is good, install a memory stick. Boot. Beep pattern should change to one long and several short beeps indicating a missing graphics card. Silence or long single beeps indicate a problem with the memory.

Insert the video card and connect any necessary PCIe power connectors. Boot. At this point, the system should POST successfully (a single short beep). Notice that you do not need keyboard, mouse, monitor, or drives to successfully POST.

Now start connecting the rest of the devices starting with the monitor, then keyboard and mouse, then the rest of the devices, testing after each step.
 

adith_neo

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Aug 17, 2010
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Tried out everything !!

Computer boots normally and works at lowered graphiucs performance without the power supply to the graphics card !

if i insert the power supply to the card, the system is dead.



Question : since the card fans turn on (obviously its taking power from the PCIx slot) , and the output is given to the monitor, then there s no prob wid the card right ? or is der a possibilty ?

also i shud check my wires to the card i guess. maybe der is an internal short or something ? but i dunno how tat could happen all of a sudden. Am really puzzled !

and searching google, i guess i'm the only person with such a weird problem
 

Cornholio

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How many watts is your PSU?
maye the new HD requires more watts, and the power supply can't deliver.
try getting a higher wattage psu.
When a PSU cant give enough power, usually the comp wont start
also, some low range PSUs do not give their labeled wattage.
I reccomend u get for 80€ the Tacens Valeo III 500W
its modular, 0db, and has been working fine for me for a month
it has also 80plus bronze.
Good luck!
 

adith_neo

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Aug 17, 2010
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Guys,
I really need to get this sorted out.

I need to find out if the prob is with my PSU or the GPU.

everything was fine b4 i plugged in the new HDD.

the HDD was just a temporary thing. I removed it once the job was done.

Now when i removed the HDD, and start the comp, it just spins up for a sec and dies.

but like i said again, when i remove the 6 pin connected of my 8800, it starts normally.

How do i Confirm whehter the prob is GPU or PSU