PC not starting up.

Keeps showing the green light on the motherboard,but does not start-up & no fans spin.Not even any beeps :-/
I also notice the motherboard has (like most motherboards) 2 pin RESET connector,but the tower I'm using does not have a Reset connector :-/
CPU has no broken pins from what I can see.

Q4950 CPU
Corsair 650w
GTX 260 GPU
Asus P5K ASUS - Motherboards- ASUS P5K
2 x 2gb Corsair memory.
Lian-Li PC7077B

Any help more than welcome.
 
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Trollslayer

Distinguished Member
Check for loose PSU connectors on the motherboard, that would stop everything.
There will be the 24 way and the separate 12V CPU power connector, make sure they are seated properly.
 
Check for loose PSU connectors on the motherboard, that would stop everything.
There will be the 24 way and the separate 12V CPU power connector, make sure they are seated properly.
Yes both are seated correctly.Even if I was to turn on the PC without a GPU & HDD then I'm sure I would receive bleeps,so not sure what's going on.
Even faulty ram would make the PC bleep :confused:
 
The PSU is brand new & arrived 2 weeks ago in a sealed box.
I'll take my kids PSU out of her PC & try it in mine & will post back.Will do this on monday due to heavy work load just now.
 

spyder viewer

Well-known Member
Has this psu worked before?
Is the power on button correctly attached?
 

EndlessWaves

Distinguished Member
What about the motherboard bios battery?
If that's flat would it stop the PC powering up?
I had to replace one once but I can't remember what the symptoms were.
No, it just doesn't remember the bios settings. This can cause it to stop booting in rare cases that the default settings don't work with the hardware but it shouldn't cause it to be entirely dead.
 
Sorry for the late reply's guys as I've been working all day.
Power must be getting to the motherboard as the green light comes on,but I would think if the Ram,CPU or even GPU where goosed then I would get some bleeps from the PC.
The battery is good as I've asked the seller about the battery & they said it's OK.
I'll strip the PC down on Monday as that's my day off.
I still can't understand why the tower does not have a Reset cable to connect to the motherboard & so not sure if that's the problem.
 

spyder viewer

Well-known Member
Only needs 5V stby for the green light to work. Check power switch connections to mobo and that reset jumper is in "correct " position.
 
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Only needs 5V stby for the green light to work. Check power switch connections to mobo and that rest jumper is in "correct " position.
Going by the manual (pdf download) for this motherboard,then everything is correct except my tower does not have a Reset cable to plug-in to the motherboard & not sure if I need it in truth.
Also not sure if a faulty CPU would stop the motherboard from booting or make a bleep noise.
 

Trollslayer

Distinguished Member
A faulty CPU wouldn't stop the cooler fan from starting, the power on circuitry starts this at full speed.
Lack of a reset connection wouldn't either as it is a simple on/off.
 
A faulty CPU wouldn't stop the cooler fan from starting, the power on circuitry starts this at full speed.
Lack of a reset connection wouldn't either as it is a simple on/off.
Yes that's what I thought & so looks like a connector is not seated properly or the motherboard or PSU are dead.
 

mdbarber

Active Member
yes a faulty cpu "may" stop the cooler from starting but unoverclocked intel cpus rarely blow these days, mainboard is likely suspect if psu checks out ok.
is this a system you have just upgraded?, check for mainboard stand offs you may have missed that dont line up with mounting points on your new board...
The reset switch pins are not relevant and can be left unconnected, make sure (if the board has it) the reset cmos pins are jumpered correctly, some people still ship items with the jumper in the reset position and this can stop a board booting.
Also (if u have a steady hand) remove the power switch connector and briefly bridge the pins to activate as occasionally stuck switches can do this.
 
OK so what I've done is take out the GPU & PSU & tried them both in the kids PC & both work fine so can be ruled out as faulty.
I've then installed all the cables back in the PC I want for gaming & have posted some photo's below as the CPU & Motherboard along with AUX are running at very high temps.
I'm not sure what AUX is & not sure if the CPU is running hot due to Zalman fan.The fan lights-up & spins,so would guess that's OK ?






 

EndlessWaves

Distinguished Member
Speedfan has simply picked the wrong sensor to label as CPU, it would shut down if it was actually at those temperatures and your BIOS showing a more reasonable temperature only confirms it. Chances are there's nothing actually hooked up to those readings and the values their showing are maximum.
 
Speedfan has simply picked the wrong sensor to label as CPU, it would shut down if it was actually at those temperatures and your BIOS showing a more reasonable temperature only confirms it. Chances are there's nothing actually hooked up to those readings and the values their showing are maximum.
So how will I know if CPU is overheating ?
Do you know a software program I can try & I'll post back results.
Are you saying CPU's can't reach this temp ?
 

brookheather

Distinguished Member
Trollslayer said:
A faulty CPU wouldn't stop the cooler fan from starting, the power on circuitry starts this at full speed.
Lack of a reset connection wouldn't either as it is a simple on/off.
Yes it can - I had a faulty Core i3 cpu which didn't start any fans.
 

EndlessWaves

Distinguished Member
So how will I know if CPU is overheating ?
Do you know a software program I can try & I'll post back results.
Are you saying CPU's can't reach this temp ?
Modern CPUs will first throttle themselves when they're getting hot (i.e. drop back down 2000Mhz in CPU-Z as they do when mostly idle rather than stay at the nominal frequently when they're under load) and then automatically shut down so I wouldn't worry about the temperature if it's working normally, CPUs rarely fail from overheating in the sort of timespan we keep personal computers for.

You can't get a perfectly accurate temperature from a Q9450 anyway, just check it with different programs and you'll see they'll provide different numbers even when running side by side - they're all estimates. If you are interested then RealTemp and CoreTemp are generally felt to give the best estimates, and let you customise them to correct any odd readings for your particular CPU. The other CPU and core temperatures in speedtemp and the bios are probably within 5-10°C of accurate though.
 

spyder viewer

Well-known Member
That's only 10degs higher than the ambient inside the case. I can't see it's a problem.
 

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