SieRobin

Here's my issue. Recently I've been having problems with my computer booting up. When I power the computer on, power comes on for maybe a second and it turns off. It cycles through this endlessly until I change, the red switch for voltage level I'm guessing, on the back of the PSU, to allow the PSU to spin all the fans on the board. Immediately as I switch it back to the correct level the power goes past post and everything is fine. The computer boots and I'm able to do whatever I want.

Now when the red switch is on the correct level and I unplug the 2x 4-pin connectors for the CPU on the mobo, everything is powered, but obviously the computer doesn't start because I have no power running to the CPU.

Could it possibly be that the PSU isn't drawing enough power to the board to power the computer fully up? Perhaps there is something wrong with the capacitors in the PSU? Is the board somehow shorting out not allowing it to start? Is my CPU dying? I'm very confused and any help would be appreciated.

My question is, does this sound like a PSU, MOBO, or CPU problem?

IvanV

Definitely looks like a PSU problem, but I beg you to not touch the 110V-220V switch, because I know of cases where things ended with a bang, smoke and the entire PC fried.

__________________
If anyone has Portal 2 and hasn't played the co-op and wants to do me a favour, let me know (PM me or whatever).

temeteus82

Can you provide more info about the mobo, PSU and CPU..

__________________

SieRobin

Sure thing. Sorry if some things come out sounding a bit ridiculous, as I am posting from my phone.

Motherboard: Asus P6X58D Premium
Processor: Intel Core i7 920 Bloomfield
PSU: Xion 850w

I'd like to thank you for the response IvanV, and thank you for the tip, I won't be touching the switch anymore.

If you need anymore information, temeteus82, let me know.

Takaharu

I'd recommend changing that PSU to a reliable brand like Corsair, Thermaltake, OCZ or the like. Xion PSUs are of the cheap variety.
If you haven't got a graphics card in those components I'd probably suggest a Corsair CX 430W. If you do, however, then if you supply us with the make & model of your graphics card we'll base it off of that.

__________________

temeteus82

Well that was more than enough.

So let me get this straight. You have issues when you pull that 2x 4 pin power connector from the mobo? As you do so the CPU isn't getting any power at all. The connector is there because the specifications in ATX 2.X states that the 24+2 pin main connector don't supply the CPU's power. So that's why there is the 2x 4pin power connectors for the CPU in the mobo. So your system is OK. Just connect the CPU's power back

__________________

Tyrsonswood

teme...... You better read his first post again. He knows this.


I'd say you PSU is faulty, but first are you sure you are getting good consistent voltage from the AC wall plug?

__________________

temeteus82

heh.. I blame that I'm not a native English speaker

So it's the dreaded reboot after post cycle ... I had that with my current setup can't recall how I fixed it. It's mainly issue in BIOS that caused the continuous reboot for me.

[EDIT] Just went all my e-mails with Asus support and it was BIOS update the issues for me ...

__________________

SieRobin

Sorry for the slow responses guys, I'm at work at the moment so it takes me some time to be able to look at my phone. However, I really appreciate all the help.

Right now I'm running a Sapphire ATI HD 6870 with Vapor-X.

I was looking into a new PSU about a week ago thinking that was the issue with the computer. XION I now realize makes cheaply designed PSU's. The one I was looking into was a Corsair Gaming Series GS700 700W PSU.

This is the link to it on newegg.com: Newegg.com - CORSAIR Gaming Series GS700 700W ATX12V v2.3 80 PLUS Certified Active PFC High Performance Power Supply

Let me know if you think this would be a good addition to my computer, generally I've heard great things about Corsair.

As for Tyronswood's question, I'm not sure as my multi-meter has run out of batteries and I need to pick some up, so I haven't tested that yet. I know I have extra PSU AC Wall Plugs, should I try switching that to see if the issue is resolved?

Tyrsonswood

If only one plug were supplying bad voltage that would be a house wiring problem or a large load on the same circuit (Like the 'fridge) You could also have a dodgy surge strip if you use one. Don't rule out all outlets being low though, which would be a problem with your power supplier...... They don't always supply correct voltage.

A weak item, such as your PSU, can fail and the clock on your desk or the radio seem fine. I had very inconsistent voltage here a few years back, the power company knew there was a bad transformer but they were going to wait for it to fail before doing anything about it. Didn't seem to matter to them that my gear was getting fried. It's always worth checking just to rule out that possibility.

__________________

Takaharu

Yep, good choice.

__________________

Judas

As stated previously... and i must stress this... NEVER EVER EVER EVER TOUCH this switch in the back UNLESS the power is PHYSICALLY disconnected from the psu and the machine is 100% off.... This not only can emediately render your psu and i've seen the rest of the components go POOF, but warranty is VOID from doing so.

ALSO NEVER EVER EVER EVER plug power into it without the switch in the PROPER POSITION. aka.. if your running 115v... then leave it at 115v.. if your runnign 230v.... leave it there.... only switch it if your moving to a different voltage.


As for the 2x 4pin... typically those aren't 100% necessary.. i know some manufacturers that just use the standard 20pin main with a single 1x 4pin...

But all the issues you are presenting makes it sound most definitely like a Power Supply issue.... likely not providing enough power...

OR you could maybe have power in your house that is "weak"... Sometimes shared power recepticals.. or even recepticals not even in the same rooms are shareing the same circut... at which point i've seen an entire kitchen and bathroom and bedroom all sharing the same one.. resulting in a computer/microwave/lights/numerous other things all running on the same circut causing a modern computer to crash/not start properly/fail to reliably work/freeze.

Generally i recommend checking for a clean isolated receptible in the house that you know is free of other garbage on the same line and running an extension cord or moving the computer into that room to "test" and see if it works....

Always start with the source and make sure it's 100% fine...

Also remember.. multimeters are only good for checking connection prior.. and during load.... and some of them don't update fast enough to pickup spikes and dips in voltages/amperages/etc...

__________________

SieRobin

Well thank you for the concise and thorough response Judas. So I didn't do anything special and my computer started up as of right now. I'm actually using it to make this post. The only thing I did was move a couple of the PSU wires in the computer around and it started just fine, no problems.

Also as stated before I opened the computer I tried other AC Wall Plugs and those didn't work either. I also tried different outlets around the house to no avail.

However, it almost seems as though it's trying to power up sometimes and you can hear the computer kick in for 2-3 seconds instead of the flat one, like it's almost struggling to start. I think we could kind of narrow this down to the PSU itself? If not, please enlighten me, I'm always up to learn more.

SieRobin

Thank you. If I can say just about 100% of the problem is the PSU, I'll be purchasing this as my replacement. c: