Computer Wont Turn On

[Sczee]

Hi all,
In January of this year some of you on this forum helped me build my current computer and it has worked perfectly (within reason) since I first put it together. However I was fiddling around with the sata cables and one of the fan connectors last night and now it will no longer turn on . My components are listed below:

CPU - E6600 with Thermalright Ultra 120
Motherboard - Asus P5B Deluxe Wi/Fi
Memory - 2x1GB Corsair 6400C4 & 2x1GB Corsair 6400C4D
PSU - Corsiar 620HX
Gfx Card - NVIDIA - 8800GTX
Sound Card - Creative XtremeMusic
HDDs - 2x Seagate 7200.10 320GB & 1x Seagate 7200.11 500GB
Case - Lian-Li V2000 Plus II (Black)
Optical Drive - Pioneer DVR-212
OS - Windows Vista Business (32 Bit)

The CPU was overclocked to 3.24GHz before I turned the computer off to move the sata cables etc. but the core temperatures were only around 60-65 degrees C with Prime 95. The motherboard is still getting power as its 'ASUS' light still glows when I turn the power on at the PSU and some of the USB ports appear to work (the lights on my mouse light up). I havent tested all the USB ports yet. However pressing the power button on my case does exactly nothing. The power/HDD LEDs don't light up, no fans start, nothing happens at all as far as I can tell. I recently purchased the 500GB HDD and the 2GB of 6400C4 but I have had that installed for a few days with no issues. Also I have tested the CPU up to 3.6GHz in the past and while it was hardly stable it still did boot so I doubt my overclock is the problem.

Any suggestions on what I could do/test would be greatly appreciated. I have the money to buy a new motherboard or CPU or whatever if I can be sure that is the problem but I dont have the money to haphazardly buy new parts until it works again . Also as this was my first self built computer I don't have a whole lot of spare parts lying around to swap in for testing purposes.

Im thinking the only things which would stop it from booting altogether are the motherboard, the PSU, the CPU, the RAM or possibly the Gfx Card (?). Although since the fans don't even start to spin up that kinda suggests the motherboard to me (me = inexperienced with these kind of things though). As an outside chance maybe (hopefully) its just the power button on the case which is broken. Is there a way to boot the motherboard manually without using the button?

Thanks for any help.

 

[stamsek]

Verify that the power button wire is properly connected to the motherboard. Second, verify that the power supply ATX connector is firmly plugged into the motherboard. Thirdly, verify that the power supple is still good.

 

[Sczee]

Verify that the power button wire is properly connected to the motherboard. Second, verify that the power supply ATX connector is firmly plugged into the motherboard. Thirdly, verify that the power supple is still good.

1st - done and yes it is properly connected
2nd - will do
3rd - how do i verify that it is still good? I know it is at least partially good since the motherboard light turns on but other than that?

Thanks

 

[Sczee]

Ok after swapping a few parts back and forwards with my flatmate's computer I have verified that the power supply is still working perfectly. I believe that this leaves me with either the motherboard or the CPU at fault. Since pressing the power button does absolutely nothing at all (no fans starting up, nothing) I'm pretty sure it must be the motherboard. I have never tried booting without a CPU installed but I assume the motherboard starts up then starts beeping or something.

If there are any holes in my logic please let me know as I plan on RMAing the board as soon as possible. I did by the way, remove every component but the board, the PSU, the CPU and a stick of RAM and this didn't help the problem.

Thanks for any replies.

 

[Fel]

You said you moved around cables... well check that everything is plugged in correctly.

 

[Tsuchiro]

your 24 pin or 4/8 pin connector for the mobo may be loose

 

[anime4u]

Do you have a mother board speaker installed? If so do you hear any beeps?

A computer with your symptoms could be anything right now including power,cpu or motherboard. Do you happen to have your computer connected to a UPC? Unstable power to your computer can cause issues up to computer failure.

You can test for power by getting a power supply tester at your local computer store or online.

 

[DrDoU]

if you have a d-bracket and owner manual hook up led bracket and look at what lights are on to tell where in the boot up process you may have a failure.peace

 

[Sczee]

@Fel & Tsuchiro

I'm and definitely sure the cables were plugged in correctly I checked multiple times.

@anime4u

The motherboard does have a speaker installed and no i have not heard any beeps. I know the power supply works as I tested it in my flatmates computer. As I said this leaves me with either the board or the CPU failing. But as nothing happens when I boot up I think it must be the board. What would happen if you tried to boot without a CPU installed? Would the fans spin up or anything?

I don't have the computer attached to a UPC but we have pretty stable power here so I'm very doubtful that that is the problem.

@DrDoU

No I don't have a d-bracket. And I'm not sure what one is either... . But I'm pretty sure the boot process just doesn't work at all so I doubt it would help if its just a diagnostic tool.

 

[Sczee]

Ok I replaced the motherboard with an Asus P5K Deluxe and everything works again (except for constant driver related BSODs but I just need to format to fix that). Gonna ebay the P5B Deluxe which broke once I get it RMAd.

Thanks for the help sorting this out people.