CPU burn outs

ccindex

A friend's CPU cut out (Athlon XP 1700, overclocked to 1.53Ghz), he tested in another friends board, Asus A7M266, running a 1.2Ghz Athlon T-bird. It failed, but after replaceing the 1.2 Athlon, that also failed. I'm beginning to think that both chips have been burnt out, but I don't understand what happened to my friends T-bird, it was working perfectly before hand.

I'm reluctant to test his chip on my board (ABit KR7A-RAID, 1900+XP) unless compleatly necessary.

Saruman

By changing chip you may have lost some of the thermal paste on the heatsink (i assume the heatsink was on when powered up.. if not thats your prob... 2 seconds is enough to burn it out!) Anyway if you lost the contact with the thermal paste then the HSF probably could not do its job right... Also its very possible it was caused by static... if your going to touch a cpu in future you might want to get an anti static band...

Oh one last thing.. i ASSUME you not only had the system powered off.. but also disconected from the mains AND press the power button again to discharge leftover power.... there is enough power left on the board to spin the fans for a few seconds.. more than enough to feck up the chips!

PPC

Its recomended to leave the power lead in because then the case is earthed and so is the board.

Iirc and athlon will reach 147*c in 7secs without a heatsink.

And i've fallen victim to the static discharge on a cpu. I killed my Athlon 1GHz this way because i didn't touch my case.

If you can rest your wrist on a bare part of the case when its plugged in and it will earth your self.
The antistatic things work aswell but you still need an earthed source.

The cpu's should have run with out thermal paste but not very well.
You wouldnt have enough surface area contact on the chip to cool properly. The thermal paste fills the grooves on the sink and the inscriptions on the core.

Saruman

Its recomended to leave the power lead in because then the case is earthed and so is the board.

Not any more... newer boards you should not leave plugged in. Basically i use the rule if the mobo has a little led on the board indicating power... then unplug and discharge it... otherwise there is a big chance you will blow something... The P4 board is the biggest culprit for this.. but the same goes for Athlon boards... Also another way of telling if you need to do it is almost all the socket A/370 etc... basically the flipchip boards.. The older Slot 1/A boards you should leave plugged in.

If you have a manual off your mobo it will tell you.. mine for instance Asus a7v333 does say to do just that.

PPC

Ahh right
So the manual has a use :rolleyes:
I normally skip those parts and goto the ones for the specialised parts like the sim card reader with my board.

Gerry

This is all horribly misleading and wrong.

Any atx board will have power going through it when the pc is switched off.
Why on earth did you think that this applies only to the current generation of motherboards, ie those supporting the p4 and athlon, and then only to boards where the manufacturer has decided to put a power led on?

.. The older Slot 1/A boards you should leave plugged in.

Again, utter rubbish. These will have power going through them since they are almost exclusively atx boards.

If you plug out the machine saruman, static will build up, and we all know how bad that is.

To safeguard components against static discharge, do one of the following things,

* Use an antistatic wrist-strap, with grounding to the case of the pc .

* If your power supply has a switch on it ( ie at the back of the pc ), switch that off and it will isolate your pc from the mains, but still leave it earthed.

* Otherwise, you can switch off the socket where you have plugged the pc in, the earth will still be connected.

* Or, (my favourite) plug in the power plug into its socket upside down, so only the earth pin is plugged in.

Then earth yourself by touching the case of the pc, if you don't have a wrist strap ( I don't bother with them myself ).

Saruman

The reason i say this, is because Intel and AMD both came into my company when their new generation of chips came out and we are specifically told by both that this was what we should be doing. Of course you must use the antistatic rist band etc... or the best way as you said Gerry are for PSU's with a switch on them to use the switch and leave it plugged in. Now i cant turn around and say sorry Intel and AMD guys... your wrong, we have always left the plug in before so whats changed?

Truth is i dont know what has changed... a difference in how the power transfers through the mobo maybe i dont know.. im only going by what i was told by their reps and what my Asus manual says. btw dont know abut the Intel guy but the rep from AMD was a tech and knew his stuff so i was inclined to believe him. I also know from experience of people who did not unplug the mains on these newer boards fried the board or chip.

If you unplug an older board and turn on power there is usually not enough power left to power it on.. newer ones there is enough for a few seconds so there must be something different.

If im wrong im wrong.. it just means that the Intel and AMD guys were wrong and that the guy who wrote my manual is also wrong..

EvilGeorge

I have to agree with Saruman in this case , the amount of engineers I have had who have blown boards and cpus before they were informed to remove the power cable on these machines have been unbelievable - since then there have been virtually none.

Can't argue with the stats.

Gerry

Yes, note that I explained different ways of isolating the pc from the live and neutral on the mains, while still leaving it earthed. I wasn't suggesting you leave the pc plugged into the live mains. On newer boards, there are much bigger capacitors used to stabilise the power supply, that may explain why they can run for longer without a psu.

The point I took exception to was that you only said you should plug the power from p4 and athlon boards, and particularly those with leds on them, whereas leaving the power in on any atx board could damage it.

Saruman

Ah... Well you see i only said that as thats what i generally do.
The newer ones usually have LED's on them.. any that i have seen anyway... and those ones i will always unplug, Or if there is a switch (there is on my new system) just turn it off there. And any of the other solutions you proposed. The older boards.. well put it this way.. i have never come across anyone who blew one while they were left plugged in even without an antistatic band. And for grounding purposes i have always told people they should leave it plugged in up until the day AMD came round with their Thunderbird's are go chip and said not any more m8!

So i was only saying thats what i generally do, did not say it was textbook do this and only this or else bang... lol

* Or, (my favourite) plug in the power plug into its socket upside down, so only the earth pin is plugged in.

I like that one.. for some reason i never thought to do that one before... shame on me!

ccindex

I took full static precautions when handeling the CPU. I left the power cable in, but it was switched off at the mains, leaving only the earth connected.

I'm almost certain it was a problem with the thermal bond, I've got some thermal paste on order from Peats, so hopefully it won't happen again. How long will a thermal bond normally last?

I thought most motherboards would automatically power down when the CPU hit about 70c. My friend probably forgot to set that up.

I'll probably need to get a new chip, will their be any problems running an XP on a T-bird motherboard?

I've heard that you need a 300W PSU when running Athlons, is this true?

Gerry

Thermal bond can actually go off after a while. I believe artic silver eventually starts separating into its different ingredients, but the ordinary white thermal paste is usually fine. Make sure that it isn't very watery though, because this will evaporate out and leave gaps.

A 300w psu is recommended for the athlon ok, though you can get away with a 250w. ( search for threads about power supplies and tbirds on this forum if you want more info )

Afaik the xp will run fine on an asus a7m266, you will probably need to update the bios though.