Fried A CPU - Why?

[bigbeark]

I put my Tyan S2466 into a case, fired it up, and kapow - the magic smoke from CPU#2.
I used a Thermaltake TR2 430 watt power supply new out of the box. It claimed to have the 30A needed on the 5v rail to support the dual athlon MP cpus.

I had the required power connectors hooked up 20-pin ATX, 4-pin auxiliary and 4-pin Molex.

Why would this happen? You can see the burn mark on the back of the CPU.

[ratdude747]

Re: Fried A CPU - Why?

check your standoffs- you could have a screw stuck between the board and the case, causing a short.

[c_hegge]

Re: Fried A CPU - Why?

Also, make sure the cooler is clipped on proberly. I had one side come undone on a Skt. A board once and the same thing happeded.

[yyonline]

Re: Fried A CPU - Why?

I once installed a Socket A heatsink backwards, it's fairly easy to do if you're not paying attention. There's a groove in one side for the plastic part of the socket to fit into. If you put it on backwards, the CPU die doesn't contact the heatsink and it overheats very quickly.

[bigbeark]

Re: Fried A CPU - Why?

I will recheck the standoffs, but the Heatsinks were positioned correctly.
I wonder if a fan could have been bad. I DID hear some squeaking noise that may have been coming from the fan on that CPU, although the fan was spinning properly. The frying was pretty well instant as soon as I turned on the power supply.

I wonder if the "on button" on the front of the case could be shorting.
This is the second CPU this case has fried this week!

[yyonline]

Re: Fried A CPU - Why?

With a dead fan, the CPU would die a slow death, not an instant one, as long as the heatsink was properly mounted.

Did it fry two CPUs in the same board, or different boards? If they were in different boards, I'd definitely check for a source for the short in the case somewhere.

If the power button were shorted to itself, it'd just turn off, since that's how it functions normally. I've never measured the power button pins to figure out what would happen if it shorts to ground or something else...Probably not much, as with some poorly marked boards I have to go on a "hunt" for the power button pins, trying to deliberately short all the different pins until I find the right pair, and I've never damaged anything doing that.

[ratdude747]

Re: Fried A CPU - Why?

squeak plus same case tells me to look in the psu. maybe a short in there... maybe the mobo tray is warped, casing a short.

this is farfetched, but i wonder if a shorted LED would do it...

[seanc]

Re: Fried A CPU - Why?

I don't think a shorted LED, or lack of power would blow the CPU.
I think trying to draw too much power would cause the PSU to shutdown, rather than any damage to other components.

Are you certain this CPU worked before being installed into the board? Perhaps it was damaged before installation.

Also, this 'case', has it fried two CPUs in the same board, in the same socket in this case?

[stevo1210]

Re: Fried A CPU - Why?

I used a Thermaltake TR2 430 watt power supply new out of the box. It claimed to have the 30A needed on the 5v rail to support the dual athlon MP cpus.

I use the same PSU in my main system, and have been for the past 3 years. Needless to say, they are great PSUs and I have installed them for many other people without an issue, so I wouldn't blame the PSU... unless yours is a lemon.

[seanc]

Re: Fried A CPU - Why?

Lemons are always possible.

[shovenose]

Re: Fried A CPU - Why?

errmm-those arent such great psus. they are nice and quiet though.
http://www.hardwaresecrets.com/article/332


edit: i had one. it exploded (not with fire) (but with a cap flying around) needless to say that caused a dead mobo.

im so sick and tired of my pcs having problems with cheap power supplies, im selling all my raidmaxes and deers and such on craiglist.

[bigbeark]

Re: Fried A CPU - Why?

I don't think a shorted LED, or lack of power would blow the CPU.
I think trying to draw too much power would cause the PSU to shutdown, rather than any damage to other components.

Are you certain this CPU worked before being installed into the board? Perhaps it was damaged before installation.

Also, this 'case', has it fried two CPUs in the same board, in the same socket in this case?

No. Two different motherboards. Both dual-cpu, one was CUR-DLS using a different PSU,
and this 2466 Tyan. It was the same socket (CPU 2) but on two different mobo's.
I like the case because it will take the full-ATX boards without a shoehorn!

[ratdude747]

Re: Fried A CPU - Why?

same power outlet? sounds like there could be a wiring fault in the outlet, sending power to the ground.

[bigbeark]

Re: Fried A CPU - Why?

Yes same power outlet. Last night we had power go out multiple times. These fried CPUs happened earlier in the week. I'm wondering if there was power spiking at that time, and perhaps these 2-CPU units are more sensitive to that.

Do UPS (uninterruptible power supplies) help smooth out power spikes and do you recommend their use?