My computer started kicking into this mode after walking away leaving it running for an hour or two:

Fans racing, screen saver frozen in motion, noises emmanating from screen or computer?. Had to depress power button 10 seconds and then turn on again. Thought it was just a sleep mode glitch but after the 3rd or 4th time, the computer would not boot up again.

Black screen, no beeps, yellow light goes on for a second when you press the power button. All three fans run constantly. Monitor works with other computer.

Have checked PSU 12V and 5V rail and they're fine. What other checks can I do?

Don't want to be stupid by running out to buy a motherboard or other part without knowing for sure what the problem is.

Thank you

Hmm - has the computer only started doing this today or has it been like this for a while? The most likely cause of this is either an overheated CPU [leave it to cool down for an hour or two if you haven't already], or bad RAM. Does the computer simply refuse to boot at all or does it start POST?

__________________
Thanks,
Ash
CF Founder
Great Webhosting. Shared starting at $2 per month. VPSes starting at $6 per month.
www.Centicero.com
Want to get in touch? Send me a PM | Do you want to continue receiving free help? Or do you want this site to close? Become a premium member.

This problem has been very intermittant for the past 2 months. It's only occured a few times though. Not sure what you mean by POST? When I press the power button on the computer, the ( Amber light on the monitor) goes on but there is nothing but a dark screen.
This is an emachines T6420 with Athlon 64 3400+
I have removed the Ram and turned it on with no change, fans still racing.

When I say POST, I'm talking about the usual self-testing process before your computer starts booting into an operating system.

__________________
Thanks,
Ash
CF Founder
Great Webhosting. Shared starting at $2 per month. VPSes starting at $6 per month.
www.Centicero.com
Want to get in touch? Send me a PM | Do you want to continue receiving free help? Or do you want this site to close? Become a premium member.

There is no post going on.

im gonna guess you need a new power supply. when my power supply went out, the computer wouldnt turn on. i heard the power supply's fans tornado. i reckon it could be the processor. but im sticking to new PSU

I don't think it's the PSU--the computer "powers on" just fine--but it stalls on the POST (stands for Power On Self Test). This could be due to quite a few things, but the simplest way to get around it (if it's a problem with a setting in the BIOS) would be to reset the CMOS--that's the thing that remembers settings in the BIOS when the computer is not on. But if there was some problem, and a setting in the BIOS got screwed up, resetting the CMOS would be the simplest thing. Typically this is done by switching a jumper between two of three pins--shorting one pair of pins keeps everything in the memory, and shorting the other pair clears the CMOS and resets the settings to stock--this will also reset your system clock as well. On nicer motherboards, it's a simple button that you press instead of moving the jumper to the number 2 and 3 pins, then putting it back on the 1 and 2 pins.

If you have custom settings in the BIOS, you'll have to re-do those. But if the system is hanging before/during the POST (and assuming you don't have catastrophic hardware failure like the CPU or RAM), it's likely the computer is stuck on something that is enabled/disabled in the BIOS which prevents it from starting up correctly.

__________________
AMD Athlon 64 X2 4400+ (@2.6 GHz)
2x1GB OCZ Spec. Ops. PC3200
ASRock Dual939-SATA2
Antec TruePower 550 watt PSU
80 GB Seagate Barracuda SATA 7200 rpm
300 GB Seagate Barracuda SATA 7200 rpm
120 GB Maxtor ATA/133 7200 rpm
ATI Radeon x1950 Pro

guyladouche,

I reset the CMOS and there was no change, no screen.

I'd still like to measure the voltage to the CPU 3.3V but don't know which wires and socket is used, to absolutely eliminate the PSU as the problem.

What other options are there to dope this thing out?

Thank you,

Hi. I think if you have an ATX power supply, the attached picture should show what lines are what. Also, keep in mind that if you have a newer computer that requires the 4-pin power connector in addition to the 20-pin connector, you should trouble-shoot that as well, and measure the voltage if possible.

Attached Images

To view attachments in this forum your post count must be 5 or greater. You currently have 0 posts.

__________________
AMD Athlon 64 X2 4400+ (@2.6 GHz)
2x1GB OCZ Spec. Ops. PC3200
ASRock Dual939-SATA2
Antec TruePower 550 watt PSU
80 GB Seagate Barracuda SATA 7200 rpm
300 GB Seagate Barracuda SATA 7200 rpm
120 GB Maxtor ATA/133 7200 rpm
ATI Radeon x1950 Pro

The first thing I would check would be the Power Supply Unit. Even though it puts out 12v. and 5v., it may not not be putting out 3v.+/-.

Remove the power supply and take it to a PC repair shop. Have them test it.

You can also purchase an ATX power supply tester for around $12 to $15. It's worth the investment, even if the power supply is good, this time.

Thanks guyladouche and Tom C,

Walked away from this problem for a week. I used a digital multimeter to check the 12V and 5V rail, so can't the multimeter be used to check for the 3.3V output, or is an ATX powersupply tester necessary? If it's necessary, where would I find one?

If my multimeter is adequate, should I remove the power supply or can I test it in the PC as I did with the other rails? I was unsure of this and didn't want to risk adding any fryed components trying to dope this problem out.

blt

Yes, you should test the 3.3v rail with the voltmeter as well--make sure you not only look at absolute voltage (if it's close to 3.3v), and also fluctuations (it should not fluctuate).

The most accurate way (IMHO) to test a power supply is to completely remove all connections from the computer, plug it in to the wall, and use either a spare power-on button you might have from an older computer, or short the "power on" lead with a sheathed wire--this will accomplish the same thing as what pressing the power-on button does. Now, I've noticed that occasionally this doesn't work with a PSU here and there, but for the most part, it works just fine. Give that a shot. I don't know of a possible/practical way to test the 3.3v rail with the computer on--because in order for the computer to be on, the CPU would need juice--but this is the rail you'll have to test.

Perhaps someone has a better/easier method--just that this is the method I've used in the past.

__________________
AMD Athlon 64 X2 4400+ (@2.6 GHz)
2x1GB OCZ Spec. Ops. PC3200
ASRock Dual939-SATA2
Antec TruePower 550 watt PSU
80 GB Seagate Barracuda SATA 7200 rpm
300 GB Seagate Barracuda SATA 7200 rpm
120 GB Maxtor ATA/133 7200 rpm
ATI Radeon x1950 Pro

PSU testers are cheap - start there. (CompUSA.com: CompUSA ATX 12V Version 2.0 Power Supply Tester - 010704 - Accessories » Tool Kits)

Video cards can cause some really odd problems, try another if available (you did mention trying the monitor on a different computer).

Or, remove all the memory and try them 1 DIMM at a time.

Just some starting places.