Power on problem

[Superelastic]

Hi folks

I've just upgraded my system with the following components:

Cooler Master Real Power 850w PSU
ASUS Striker Extreme Motherboard
2gb OCZ Ram
Intel Core 2 Duo E6700 Processor

Everything's plugged into the right slots and the m/b and psu are lit up but when I turn it on it usually powers up for about 1/2 second then powers straight down. Ocassionally, and for no obvious reason, it powers up fine and runs perfectly. The same effect is true if I power on from the case button or from the motherboard (which has its own power switch).

Also, I left the machine plugged in (but powered down) overnight and when I tried to switch it on nothing whatsoever happened. Unplugging the power cable, leaving it a few seconds and then reattaching it led me back to the half second fan spin scenario (both the CPU fan and the PSU fan run during this time).

I suspect its a PSU supply problem, but I'm not the most experienced at this DIY stuff so would welcome any thoughts on whether it might be another component or whether there is a fix, before I return the PSU.

Cheers
Superelastic

 

[evongugg]

You might have a short in the case that is causing it to power down. Check you motherboard supports. Check your electrical connections also.

 

[Superelastic]

Thanks for the replies.

mpilchfamily =>

My graphics card is an NVIDIA 7800GT.

Strangely, the PSU doesn't have a power switch (according to the website it would have a tendency to catch fire) apart from that I'm a little dubious about sticking bits of metal into anything connected to the PSU. The thing does work, it's just wierd that it will start fine occasionally but generally just for less than a second.

Could you recommend a good 850w PSU?

evongugg =>

Can't find a list of supported PSUs but the short sounds like a possibility, particularly as its intermittent.

 

[evongugg]

Sorry, my mistake, I meant motherboard standoffs. Check if you have any extra unneeded standoffs. They could be shorting the motherboard.

 

[Superelastic]

Aye, that's what I always thought - this from the faq (translation is a tad sloppy):
-----------------
Real Power Pro 850W [ RS-850-EMBA ]
Q: Why Cooler Master 850W PSU without Power Switch?
A: 1. Currently PC on/off action can be done by operation system (PS _ON signal can control on/off of PSU). Therefore, the power switch is not necessary.

2. CM 850W PSU is a high wattage power supply and its relative input current is extremely high than normal power supply. Therefore, the power switch will require supporting such high current going through. However, these kind of switches with safety are rare in the market now and the reliability is not good enough. And that’s why Cooler Master will like get.

3. The most important reason why we do not design the power switch is to avoid the electronic damaged by inrush current. Real Power Pro 850W PSU is a high capacity PSU. The input current is about 15 amps in worst case. However, the transient inrush current will be 150 amps ~ 200 amps high in the worst case and this high current will cause extremely high temperature. The heat can even melt the metal reed inside the switch. Due to this safety concern Cooler Master decide not include power switch in our high power output model power supply.
------------------


I'll check out that PSU

 

[Superelastic]

Well, turns out it was a problem with the coolermaster PSU, now replaced with an Enermax Galaxy 850w which is quieter, has a power button and plenty of room for expansion. Bonus!