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Computer Wont Turn On. Help Plz

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November 5, 2011 3:02:02 AM

Hey everyone,

First of all here's my system:
- Gigabyte GA-990FXA-UD5
- AMD Phenom™ II X6 1090T Black Edition 3.2GHz
- MSI 560GTX-Ti Twin Frozr II GeForce GTX 560 Ti 1GB
- Western Digital 1TB Caviar Black 7200rpm SATA III w/ 64MB Cache
- Corsair HX 750W Power Supply
- G.SKILL Ripjaws Series 8GB (2 x 4GB)
- Antec Nine Hundred Advanced Gamer Case
- Asus DRW-24B1ST 24x DVD-RW Drive

This is my first build so if i say/do anything stupid please let me know.

So i put all the components together and did all the electrical (I'm 90% sure i did it correctly and all connections are good). What are some things i could have messed up or what could i be missing? I read in the mobo manual that if the system doesn't start it could be due to either the psu, mono, or cpu.

If you have any input at all please post it, any help would be great. Thanks

More about : computer wont turn plz

a c 78 B Homebuilt system
November 5, 2011 3:12:56 AM

First of all, are you using the separators between the case and the motherboard?

If you don't do that, it will never start.
November 5, 2011 3:15:52 AM

Yes, all the rubber spacers are in between the mobo and case.
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a c 78 B Homebuilt system
November 5, 2011 3:18:48 AM

I am not used to these being rubber, they have usually been metal in my experience.

Are these rubber things at least about half an inch thick to give at least that distance from the motherboard to the case?
November 5, 2011 3:19:06 AM

First answer is a good one,also ,some cases provide a switch at back of case to keep motherboard powered up and must be turned on.
November 5, 2011 3:23:58 AM

Also,look over all connections,in particular,the ones from power to mother board,re seat ram...have have power supply tested.
November 5, 2011 3:24:47 AM

I dont believe the spacers are half an inch long but there's definitely a space between the case and mobo. There is no switch on the back of the case. Another thing i should have added was that i also put in a Cooler Master Hyper 212+. might that cause a problem?
November 5, 2011 3:26:09 AM

My power supply hasnt been tested (if thats what you meant)
November 5, 2011 3:29:57 AM

Mike DET said:
Hey everyone,

First of all here's my system:
- Gigabyte GA-990FXA-UD5
- AMD Phenom™ II X6 1090T Black Edition 3.2GHz
- MSI 560GTX-Ti Twin Frozr II GeForce GTX 560 Ti 1GB
- Western Digital 1TB Caviar Black 7200rpm SATA III w/ 64MB Cache
- Corsair HX 750W Power Supply
- G.SKILL Ripjaws Series 8GB (2 x 4GB)
- Antec Nine Hundred Advanced Gamer Case
- Asus DRW-24B1ST 24x DVD-RW Drive

This is my first build so if i say/do anything stupid please let me know.

So i put all the components together and did all the electrical (I'm 90% sure i did it correctly and all connections are good). What are some things i could have messed up or what could i be missing? I read in the mobo manual that if the system doesn't start it could be due to either the psu, mono, or cpu.

If you have any input at all please post it, any help would be great. Thanks


Correct standoff placement behind board is critical... assuming it's correct and you press front power switch do the fans engage? Any sign of life? If no then I would re-check the front panel switches (pwr, reset, led, etc) to the corresponding header on the board.



November 5, 2011 10:00:56 PM

Can you explain "standoff placement"please?
November 5, 2011 10:11:36 PM

I'd put my money on the powersupply, My buddy had the same power supply as you and it worked, but after 2 weeks it wouldn't turn on. He tried a cheap one and bam it started and he then went though the RMA process with Corsair which went well i have to say.
November 5, 2011 10:31:47 PM

Just for the record, no light turn on or anything. If the power supply is plugged in and the switch on the back of it is turned on, should the fan on the psu turn on?
November 5, 2011 10:53:01 PM

Mike DET said:
Just for the record, no light turn on or anything. If the power supply is plugged in and the switch on the back of it is turned on, should the fan on the psu turn on?


Not necessarily, built in circuitry will prevent a PSU from powering on due to a short... Take it out and test it with a digital multimeter ($10-15 from Walmart) or breadboard your hardware (follow guide provided) to eliminate a possible short.
November 6, 2011 4:46:48 PM

So i figured out i has the HDD LED, PWR SW, and RESET SW in TPM not F_PANEL (stupid me). It still won't start... would it fry the mobo if i turned on the power with these connectors in the wrong place?
November 6, 2011 5:54:25 PM

Mike DET said:
So i figured out i has the HDD LED, PWR SW, and RESET SW in TPM not F_PANEL (stupid me). It still won't start... would it fry the mobo if i turned on the power with these connectors in the wrong place?


I don't think so... the front pant connections are just switches... but I could be wrong.

Have you checked to see if the power supply works at all; plug one of your case in and see if it gets power.
a c 122 B Homebuilt system
November 7, 2011 1:37:46 AM

Work systematically through our standard checklist and troubleshooting thread:
http://www.tomshardware.com/forum/261145-31-read-postin...
I mean work through, not just read over it. We spent a lot of time on this. It should find most of the problems.

If not, continue.
The following is an expansion of my troubleshooting tips in the breadboarding link in the "Cannot boot" thread.

I have tested the following beep patterns on Gigabyte, eVGA, and ECS motherboards. Other BIOS' may be different, but they all use a single short beep for a successful POST.

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

Breadboard with just motherboard, CPU & HSF, case speaker, and PSU.

Make sure you plug the CPU power cable in. The system will not boot without it.

I always breadboard a new build. It takes only a few minutes, and you know you are putting good parts in the case once you are finished.

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. Remember, at this time, you do not have a graphics card installed so the load on your PSU will be reduced.

If no beeps:
Running fans and drives and motherboard LED's do not necessarily indicate a good PSU. In the absence of a single short beep, they also do not indicate that the system is booting.

At this point, you can sort of check the PSU. Try to borrow a known good PSU of around 550 - 600 watts. That will power just about any system with a single GPU. 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=yout...

A way that might be easier is to use the main power plug. Working from the back of the plug where the wires come out, use a bare paperclip to short between the green wire and one of the neighboring black wires. That will do the same thing with an installed PSU. It is also an easy way to bypass a questionable case power switch.

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, long single beeps, or series of short beeps indicate a problem with the memory. If you get short beeps verify that the memory is in the appropriate motherboard slots.

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.
At this point, if the system doesn't work, it's either the video card or an inadequate PSU. Or rarely - the motherboard's PCIe interface.

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. It's possible that you can pass the POST with a defective video card. The POST routines can only check the video interface. It cannot check the internal parts of the video card.
November 7, 2011 2:05:10 AM

/\ +1

I think breadboarding is the first step. As it eliminates any case problems...
November 7, 2011 2:06:00 AM

.
!