Issue: PC won't boot up (not even POST)

ixoy

I came home today and my PC would not boot up and I'm looking for help...

PC Setup:
========
Processor: i5 Quad Processor i5-750
Mainboard: Gigabyte GA-P55A-UD3
Graphics Card: Radeon HD 5850
Case: Cooler Master HAF 922
Power Supply: Corsair HX 650W PSU
Cooling: Cooler Master Hyper 212 Plus CPU Cooler
Memory: Crucial DDR3 BallistiX 1600MHz 4GB CL8

What's happening:
=============
* Fans start up - power is being supplied to the mainboard. This includes chassis fans, CPU cooler fan, and GPU fan.

* No output issued at all to the monitor.

* No POST beeps issued from the mainboard/BIOS on startup

* There's one set of LEDs on the mainboard - according to the manual this is the "Phase LED": The number of lighted LEDs indicates the CPU loading. The higher the CPU loading, the more the number of lighted LEDs.
These LEDs light up for about 15 seconds and then turn off. Power is still being supplied to the mainboard (all the fans keep going) but these lights, I believe, shouldn't be off. I'd swear they used to always be on.

* Possibly unrelated: Yesterday the PC lost a USB connection to an external drive a couple of times. This had never happened before. It was fine on a restart. I attributed it to the fact I had connected a new smart phone on the time and that caused a conflict.
I also used the "Sleep" function for the first time recently.
Additionally I thought I had powered it off on Saturday but it appeared switched on when I went down that morning - could just have been tiredness.

What I tried:
==========

* Opened the case and checked all the power connections to the mainboard.
* Re-sat the memory chips
* Re-sat the graphics card

What to Do:
=========
So what is there left to try? Is it worth taking a graphics card from a different PC? Are the "Phase LEDs" on the mainboard a bad indicator or could they just turn off if something else stopped the boot up process.

hearny

My first suspect would be the PSU, If you can replace it.

If you have more than one RAM Module try it with only one.
If it doesn't work use the other.

Disconnect as much peripherals as you can (DVD / HDD etc.) Obviously without hard drive connected its not going to boot but you would get POST screen if its going to work.

hearny

Sorry I meant to say definitely check with another graphics card.

ixoy

hearny wrote: »

My first suspect would be the PSU, If you can replace it.

It supplies some power - e.g the fans start up. Does this not mean that the PSU is working? Or could it be that it's not supplying enough wattage.
I have another PSU, of equivalent strength, that I could try.

If you have more than one RAM Module try it with only one.
If it doesn't work use the other.

Yes, I could try that. It seemed well seated though, as did the GFX card. No harm in experimenting further.

I only assembled this PC in February and it was done very carefully.

hearny

Check the Other PSU as it supplies different voltages for different areas of the motherboard so its the most likely cause other than the mobo

ixoy

hearny wrote: »

Check the Other PSU as it supplies different voltages for different areas of the motherboard so its the most likely cause other than the mobo

That makes sense. I really hope it's not the motherboard itself!
Do these devices have any sort of warranty? They're only nine months old.

massy086

have u cleared the cmos on the mobo

hearny

They should have a 12 month warranty, was it a self build or did you get the PC pre built.

Where did you get it from.

ixoy

Right - some progress! I swapped in an old PCI graphics card and the PC booted up. I swapped back in my fancy Radeon HD 5850 and again it failed to boot. Performed the swap again: same results.

So it appears to be the graphics card that's the problem. Can I be sure of this? My backup PC is old and wouldn't support the Radeon so I can't check it there.
The Radeon draws more power than the older card would: it's a PCI x 16 and the recommended input is a PSU with 500W. Mine has 650W and there's really not much other load on the system - a number of USB devices, 2 internal IDEs and 1 DVD drive. 650W should be plenty. Is it possible that it's still the PSU though that's gone faulty that it can't support the load any more? Could it be the single PCI x16 slot on the mainboard is broken? Or am I grasping at straws and the 95% likeliest explanation is that the GFX card is broken (which was ordered online only last February!). I'd just like to be feel confident that the GFX card is the issue before I look at replacing it (it wasn't cheap!).

hearny

It doesn't look too cheap anyway.

The System requirements for that graphics card on the AMD site show:

500 Watt or greater power supply with two 75W 6-pin PCI Express® power connectors recommended (600 Watt and four 6-pin connectors for ATI CrossFireX™ technology in dual mode).

Im assuming you only have the one card so try to power it with one of the other 4 6 pin plugs.

You are right to try to make sure that the card is dead before trying to get it replaced.

Does the replacement card need power from the 6 pin plug too.

The PSU should be more than capable of running your setup, you can check your consumption here: http://www.thermaltake.outervision.com/

ixoy

In case anyone ever comes across this thread, thought I'd better post a conclusion

It WAS the graphics card. I managed to try it in my old PC and it produced the same result as with my new one. Sent it back and got a refund.

When I put in a new graphics card, it worked fine. Thanks for the help!

Nothingbetter2d

As most motherboards store power in capacitors for up to 60 seconds they have issues with pulling cards/ memory chips out

try this.

step 1 power down the pc

step 2 count 60 seconds then pull out power cable

step 3 count 60 seconds then reset cmos and plug in power cable

step 4 power up