Power SUpply Problems

[Prime_thor]

Need some input from others who maybe able to shed some light on my PSU problems

I got a 850W Seasonic X over 12 months ago, and a few days ago, the unit just suddenly for no reason just went kaput. Won't respond.

My setup at the time qas using a q6600, mild overclock to 3.2, 8GB ram, mianbaord is Asus p5q pro. I am using a Corsair H80, Gigabyte GTX460 SOC, which a good 99% of the time was just using at stock speeds, 3 HDDs, but only 1 mainly being used, 1xdvd drive, 5 fans all up 2 on h80, top mounted fan, and 2 front intake (antec 902 case).

When it last worked, there was no sign of any power issues or anything, but the next dayt it was just a sudden death.

Looking at my motherboard, I can see the light of the motherboard showing when I switch the back of the PSU to on, but other than that, it is dead. I have tried this on another PC build, it still refuses to work.

I took out a multimeter to check the motherboard cable in case the cable was a problem, but the cable checks out.

I was lucky to borrow a COrsair 620W PSU off a friend for the time being until I can get this PSU of mine fixed up (which at the moment, just put my q6600 back to stock speed).

My freinds setup was similar to my build, except for a 8400 CPU and GTX275 and as far as I know, GTX275 used up more power than GTX460 1gb.

IS it possible the 12v rail failed?

 

[FlintIronStagg]

Although seasonic are quality psus, there is a percentage of fail rate with any brand.
What is their warranty like?

 

[jsc]

Almost anything inside the PSU could have died.

The only thing that we know works is the auxillary power supply. That is a small independent conventional 5 volt power supply. That turns on the motherboard LED.

If the system is completely dead, the problem could be:
1. The startup circuits. They respond to the case power switch and get things going.
2. Main power outputs. You need all three: 3.3, 5, and 12 volts.
3. The Power_OK signal. This is a control signal that the PSU generates when the 3 main output voltages are stable. The CPU needs this signal to start running the POST.

Use a DMM to measure the voltages. Measure between the colored wires and either chassis ground or the black wires. Yellow wires should be 12 volts. Red wires: +5 volts, orange wires: +3.3 volts, blue wire : -12 volts, violet wire: 5 volts always on. Tolerances are +/- 5% except for the -12 volts which is +/- 10%.

The green wire should be 5 volts whenever the PSU is plugged in and the PSU switch is on. It will drop to about 0 volts when the case switch is pressed and go back to 5 volts after it is released.

The gray wire is really important. It should go from 0 to +5 volts when you turn the PSU on with the case switch. CPU needs this signal to boot.

An overclocked Q6600 will not pull more than about 25 watts more than normal so there is no reason to disable the overclock.

I doubt if your system is pulling more than 350 watts from the PSU. One of my systems has an OC'd Q9550, 4 GB RAM, a GTX260 - a card with similar power requirements to yours, a Gigabyte EP45-UD3P motherboard, 3 hard drives and an optical, and a Soundblaster card all powered by a Corsair 750TX.

Running 3 instances of Prime95 to load the CPU and 3DMark06 to load the GPU, it pulls 375 watts from the wall as measured by my Kill-a-Watt meter. Figuring 80% PSU efficiency, the system pulls 300 watts from the PSU.

 

[Prime_thor]

Thanks for the replies. I got that extra powerful PSU as I was thinking ahead for when I do other system upgrades, and have a good PSU already.

ANyways, I still got reciept and it is a warranty issue. So I will be taking the matter up either with the place I purchased from, or dealing with the authorised importer of the Seasonic power supplies. (I live in Australia).

 

[totalknowledge]

RMA it.

 

[Prime_thor]

RMA it.

Done that yesterday. Spoke to my local distributor, explained the situation, took a copy of my purchase receipt, paperwork filled out.

After spending the past week going through all sorts of scenarios, testing my PSU on a different computer setup, having the same result, not always booting when power switch is pressed, having to turn off switch from back off psu, and on again just to get the sytem to boot, and that method doesn't always work.

Doesn't always want to power on this PSU, pressing the power on button from the computer is not always working. 2 different pc builds the same result, but using the COrsair 620W I currently have on loan, my main PC now works perfectly. (this is the pc the X850 was used on ).

The most interesting thing I notice the other week when gaming, is that not once did I notice the fan ever turn on, a brief moment as it boots up and thats it, as it is a hybrid type (fan kicks in after areaching a certain temperature, and load).

Now I got myself a wattage meter today to work out how much watts my system draws, and for gaming like black ops and mafia 2, enough was drawn to make me believe the fan should of kicked in, but few days ago when I played black ops, not once I notice the fan moving, either the PSU was under 25 degress celcius when gaming, or whatever mechanism automates the fan to turn off or on is defective, resulting in the fan not able to operate, and over time, somethign could of overheated or gotten damaged.

In my personal experience over the years, a computer unable to boot properly is either ram problems, motherboard, or psu. After all my testing, I have no doubt its the PSU (it may well of been defective when I purchased it but didn't know, it is possible).