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Starting up without BIOS?

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January 22, 2008 2:46:18 AM

Hey all,

Last night I opened up my tower to lay down a new dab of thermal paste on my CPU. It's been running at 55 celcius lately and the fans have been whining like mad.

But after fastening the heatsink back down, the computer won't boot into BIOS anymore. Everything will power but nothing actually happens.

This is the second time this has happened. Last time the store told me to buy a new PSU and it worked, but I've only had it for a few months now and once again this is happening conveniently after I've removed and fastened the heatsink. It can't REALLY be a PSU issue, surely. It's new and I haven't even touched the thing.

What's really the problem here?

More about : starting bios

January 22, 2008 2:50:05 AM

Are using a conductive thermal paste? Like AS5? Maybe it got on somewhere?
January 22, 2008 2:56:05 AM

I'll have to check when I get home.

Someone has suggested resetting the CMOS, is that a good idea?

I should clarify that by 'BIOS' I actually mean POST. The usual startup beep doesn't sound anymore.
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January 22, 2008 2:58:36 AM

Pogotron said:
I'll have to check when I get home.

Someone has suggested resetting the CMOS, is that a good idea?

I should clarify that by 'BIOS' I actually mean POST. The usual startup beep doesn't sound anymore.

Yes.

Simply remove the battery and wait for a minute or so.
January 22, 2008 5:16:04 AM

I'm with the dragon on this one.
You probably inadvertently pushed one of the mem retainers down.
It could also be a loose power cable, gfx card, or if it's an AMD chip, you may have put it in wrong way round.
BTW it sounds like your original problem was dust in the hsf. Blowing the dust out is still a good idea. It was probably all you needed.
January 22, 2008 10:08:41 AM

Was HS fully engaged? Very common for one pin to pop out of engagement. Was tha 55C idle or under load? For a Preshot 55C under load is good. :) 

Mike.
a c 172 à CPUs
January 22, 2008 10:46:40 AM

The only thing you did was something physical. So look for a physical cause of your problem. Verify that the HSF is properly installed. Double check all cabling. Going as far as disconnecting everything then reconnecting everything is not a bad idea.

After that, try this:
http://www.tomswiki.com/page/Troubleshooting+a+New+Buil...

It is, as the title suggests, oriented at a new build, but you should find some useful ideas.
January 22, 2008 11:04:30 AM

I run into something similar on my Asus P5W DH motherboard. Do something to it, like install a new power supply, and it just won't turn on. No beeps, no lights, nothing. Tried resetting the CMOS memory with the jumper, still nothing. The only thing that worked was disconnecting the 24 pin power connector to the motherboard, then it started right up. This happened to me several times over the weekend as I upgraded a number of components.

Clint
January 22, 2008 1:32:43 PM

Okay guys, many thanks.
Since last posting, the system is now occasionally powering down just seconds after powering up. It's amazing - history is repeating itself perfectly.

RAM is not a problem. Swapping the sticks around and ensuring everything is tight resolved nothing.

The heatsink is firmly and securely fastened down to the CPU with a new layer of thermal paste. Nothing.

Removing the battery for a few minutes and then replacing it resolved nothing.

Clearing the CMOS with the jumper resolved nothing.

I have to be honest guys, how the application of new thermal paste to the CPU can bring a system to its knees like this is far beyond me. I don't understand it.

I can't take someone seriously when they tell me my PSU has died twice by shear coincidence when merely applying new thermal paste to the CPU. In whose book does this make any amount of sense?

I'm reluctant in taking this matter back to the store because they'll just tell me to get another new PSU when I honestly think there's nothing wrong with what I've got. If I have to buy a new PSU every time I put down new thermal paste, then it seems my knowledge here is even thinner than I thought.

Quote:
The only thing that worked was disconnecting the 24 pin power connector to the motherboard, then it started right up.


I'll give this a go! Hell, I'll try anything.

Once again guys, many thanks for the help. I want so desperately to fix this because it seems like it's going to happen again and again if I don't find out what's REALLY causing this problem!
January 22, 2008 1:39:21 PM

You can test the PSU without the MB hooked up:

Powering an ATX PSU Without a Motherboard

Basically your connecting the green and black wires on the 24 pin (should be same on 20 pin) with the PSU power off. So when you plug it in, and flip the power on the back of the PSU, it should come on. You can also test the voltage with a volt meter if you have one handy.
a c 172 à CPUs
January 22, 2008 8:32:44 PM

And then with a DMM, check the voltages:

Yellow wires: +12 volts
Blue wire: -12 volts
Red wires : + 5 volts
Orange wires: +3.3 volts
Violet wire: + 5 volt standby (I think)

Grey wire: +5 volt control signal. PC NEEDS this to boot.

These can be checked under load from the back of the PSU connectors while plugged into the mother board. The grey wire should rise to 4.5 to 5 volts within .5 sec. after pressing the power switch. If it then drops to zero when the PC shuts down, either the PSU is bad or something in your system is shutting the PSU down.

January 23, 2008 11:20:53 AM

I'm not keen on touching things I don't understand.

Someone mentioned changing their fan speed from automatic to manual, would this really be a problem?

I think what I'm going to do is take everything out and rebuild it out of the tower.
January 23, 2008 8:43:35 PM

is it possible that you damaged the mobo when you reapplied the heat sink. what i mean is if you put the heat sink back on with the mobo still in the case then the mobo was still mounted on standoffs and might have space underneath the cpu socket. the downward pressure on the cpu when you reinstalled the heat sink and the clip (if it has one) might have bent that area of the board causing damage. maybe broken traces? it a longshot, but not impossible, especially if it's an older board or if you've put pressure on that area of the mobo before under similar conditions. just my two cents...
January 23, 2008 9:09:51 PM

I don't think the changing the fan to manual is going to do much for you. it sounds like you may have unplugged something that just isn't getting a a good connection. you might just be over looking something. I don't think you have broken any traces. you have to realize is that you are a public forum have of these people on here don't really know what they are talking about. good luck
January 23, 2008 9:17:29 PM

Quote:
it a longshot, but not impossible, especially if it's an older board or if you've put pressure on that area of the mobo before under similar conditions.


notice the part where i said "it a longshot"? (oops, should have been it's a long shot.) as for unplugging something that would cause that , it would pretty much have to be the main ATX connector, the aux cpu power, or maybe the power switch cable.
January 24, 2008 1:54:06 AM

I've double and triple checked all the connections but everything is fine.

Last night I replaced the PSU for testing purposes and there was still no post or beeps. At this point I'm assuming either the CPU or the mobo has flopped.

Quote:
the downward pressure on the cpu when you reinstalled the heat sink and the clip (if it has one) might have bent that area of the board causing damage


This is possible. My heatsink requires a particular amount of elbow grease and frustration to get it secure, so admitedly that area of the mainboard has seen its fair share of pressure over the past two years. However, this still doesn't explain why a replacement of the PSU last time seemed to solve the problem. Or does it?
January 24, 2008 4:32:49 AM

you're right. it doesn't explain why a psu replacement fixed it the last time, unless last time it really was a psu fault. the only other thing i can think of is static discharge damage. just because you don't feel or hear the normal "pop" of the shock, it can still happen. i learned this the hard way. good luck with the fix. i'll chime in if i think of something else. let us know what happens, i'd love to hear.
a b à CPUs
January 24, 2008 6:17:59 AM


The trouble here with you situation is that you dont have spares of anything which a computer dealer would have.

Normally if the psu is knackered and it still powers on there would be some beeps, Im not saying it isnt the power supply but im not sitting in front of it.

CPUS dont normally go wrong, its not unheard of but normally they are ok.....

Now Motherboards go very common next inline - going from hard disks, power supply, motherboard and video card roughly the same.....

Take out the video card and see if that posts ( beeps).

Put onestick of ram in at a time and see if that posts.

Take out both sticks of ram see if that posts.

Take out the processor again and see if there are any damaged pins.


In future it would be good to know what beast we are dealing with - ie Intel or AMD and what socket it is from the start to get an idea what the problem is.......

Also what motherboard is it ie model and make as Asus's have been known to be tempermental..
January 25, 2008 12:12:02 AM

As shown in my info, the chip is a Pentium4 3.0ghz HT designed for an LGA775 socket. My mobo is a Gigabyte - a choice I had to make over Asus due to budget reasons at the time (which I think is roughly two years from now)

I've tried booting without the video card and also by swapping/removing/isolating the ram sticks, but still no luck.

There was a time when this started happening that the system shut its self down after a minute or so and the whole CPU and HSF was incredibly hot. The HSF was properly fitted and there was nothing else I could do to cool things down. After that, neither the HSF or the CPU even warmed up. Sounds like something has cooked but I'm not jumping to any conclusions!

I took the whole tower to a local computer store yesterday and they told me my PSU was fine and that everything fully booted after replacing the CPU. They were reaching the conclusion my CPU was fried but weren't entirely sure.

Come this Tuesday I'll have a new Asus P5KC, 2gb of DDR2 and an E6750 Core 2 Duo. Should be a decent upgrade for someone like me constantly rendering video and 3D overnight, and it should be interesting to see how this heat-pipe cooling system works out for me.

Again, many thanks guys. I appreciate the help a lot!
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