Computer Help forum


Computer won't boot or turn off

by Tankmonster / March 15, 2016 12:29 PM PDT

I built a pc from some parts I had laying around and new ones I bought. When I went to turn it on it starts up normal for a fraction of a second and the the fans go to full speed and it won't boot even into bios and it won't turn off unless you unplug it.I've tried removing the hard drive, graphics card and ram. When the ram is removed it doesn't beep or anything just spins up.

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Clarification Request
We need more info
by itsdigger / March 15, 2016 1:33 PM PDT

Without knowing anything, I would have to ask if your monitor is working or are you sure the monitor is getting a signal?

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by Tankmonster / March 15, 2016 3:51 PM PDT
In reply to: We need more info

Yes it works.

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Clarification Request
Old and new parts?
by Steven Haninger / March 15, 2016 1:53 PM PDT

What is old and what is new? Old MB could mean BIOS battery needs to be replaced and BIOS reset. New MB w/old PS might not have proper CPU PS connector. Try giving more details about these parts as old and new could be either a compatibility problem, parts failure or assembly issue.

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New old parts
by Tankmonster / March 15, 2016 3:50 PM PDT
In reply to: Old and new parts?

Old mother board, psu, ram and cpu they are only 2 years old. new gpu. The ram, mobo and psu are just generic from a dell xps8700 the processer is I5 quad core 3.0 or 3.5 ghz. The gpu is gtx 960

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Old power suppy
by Steven Haninger / March 15, 2016 5:08 PM PDT
In reply to: New old parts

I'd make sure the old PS was capable of handling the new graphics card. Most proprietary systems are thin in the PS area with little room to add much more than an additional hard drive. I'd still check the BIOS battery. Take it out and leave it out for a while. If you have a DVM or access to one, make certain its output is above 3v. I've seen them work down to about 2.5v but I've also seen them be useless at 2.9. Replace it if under 3v. If you've moved the MB to another case, check and double check that no metal standoffs that don't line up with a mounting hole got left on the back plate where they can contact the non-component side of the board.

All Answers

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Let's get some model numbers in here.
by R. Proffitt Forum moderator / March 15, 2016 5:17 PM PDT

The twitch of the PSU is a sign of a short or overload.

I'd like to read more detail since I don't know if it's a motherboard mount issue, the old IDE drive issue or other.

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Maybe the power switch...
by Oldartq / March 15, 2016 7:18 PM PDT

malfunction. It's making contact all the time instead of momentary contact. Just guessing.

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Power switch
by Tankmonster / March 15, 2016 7:52 PM PDT

How would I check if it is the power switch

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Make it smaller
by Bob__B / March 15, 2016 10:21 PM PDT


Locate the two pins on the mobo that the power on switch connected to.
Short those pins for about one second.
It should power up.

Now short those two pins again for about one second.
It should power down.

If this does not work move the mobo to a piece of cardboard and retest.

If it still fails your down to three parts or the bios battery....change it it's cheap.

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(NT) Maybe the power switch.
by jeanramar / March 16, 2016 12:36 AM PDT
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Re:Computer won't boot or turn off
by appkodes / March 16, 2016 10:19 PM PDT

It should be either your Motherboard or CPU being damaged.
You could try using another CPU just to confirm your CPU isn't dead.

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