Start-up 1

[Guest_imported]

I have the next problem,

When i start the computer, i see that it is a 400 Mhz and have 128 Mb memory after that the coputer shut down.

I saw that the fan in the power suply was broke so i change the fan. But the computer its still broke.
Then i change the hole power suply, and i see only the speed and the memory, after that the computer shut down directly.

The motherboard is a P2B asus.

I think that the bios is broke or there is a security.

I hope someone can help me

Rob. The Netherlands

 

[paulwood]

I think it is unlikely that it is a security problem. Unfortunately it looks like your motherboard or hard disk may have been damaged by high temperatures when the fan stopped working. Do you get the option to access the Bios or does it stop before that?

 

[Guest_imported]

Its stop befor i can go in to the bios

 

[Guest_imported]

it stop befor i can go in to the bios

 

[paulwood]

The most obvious reason would be that the motherboard needs replacing, since even if it is the Bios you would need at least the floppy drive working to re-flash the Bios. One other thought I had is that there are viruses around that will kill the Bios by erasing it. Was your anti-virus protection up to date?

Either way

http://www.asus.com/Products/Motherboard/Pentiumpro/P2b-ds/

is the technical support page for the P2B-DS, if this is not your board I'm sure you will be able to find the right page.

 

[pjs]

Before you replace the motherboard:

Make sure the power supply connector is firmly and properly inserted on the motherboard's power supply connector.

Does the cpu fan spin up? Cpu heatsink properly seated on the cpu? If you are overclocking, set things back to their rated speed.

If there is, on the motherboard, a cmos memory reset/clear jumper (to reset the bios cmos memory to the default settings), put the jumere to this clear/reset position for a few seconds (10 or so seconds) and then back to its default position.

Try starting the computer. If this works, then you will need to go into the motherboard's bios setup and change settings that you need changed.

Let us know what happens.

Paul

Paul J. Stiles
stilespj@mindspring.com

 

[pjs]

Another thing to try is to reseat the cpu: pull it out and plug it back in, making certain that it is properly seated. I have had this fix a non-start problem on a couple of occasions.

It is best to try these troubleshooting tests with the minimum system: only a cpu, memory and video board. Remove, for testing purposes, other cards and perhaps even disconnect the drives from the motherboard.

If you can borrow another cpu and/or memory to try, then this may help narrow down where the problem is.

Paul
Paul J. Stiles
stilespj@mindspring.com

 

[pjs]

I thought of something else.

If you can, also try your cpu and memory and perhaps video board in a different system (one at a time, then in combinations). If these all work OK then this would point to the rest of your system such as the motherboard, power supply, or hookup problems.

If you have access to a voltmeter, it would be a good idea to verify that the power supply is giving the proper voltages.

ATX pinout (20 pin connector to motherboard)

Pin Signal Pin Signal
1 3.3V 11 3.3V
2 3.3V 12 -12V
3 GND 13 GND
4 5V 14 Pwr_On
5 GND 15 GND
6 5V 16 GND
7 GND 17 GND
8 Power_Good 18 -5V
9 5V_Standby 19 5V
10 12V 20 5V

GND is usually black, 5V is usually red. 3.3V is usually orange.

Pin 9 should have 5v on it whenever the power supply is plugged into the wall and the back panel switch on the supply is on and getting proper ac voltage.

Connecting pin 14 to ground will turn on the supply and you can measure voltages at the various pins. Be aware that the voltages may not be at their proper values, (or the supply may not turn on until there is a minimum load on the 5v line) unless a load (such as a motherboard or resistors of reasonable value) is connected.

Paul


Paul J. Stiles
stilespj@mindspring.com

 

[AndyHo]

I had a faulty power supply that caused something very similar in a machine running an AMD K6 500 chip. It would run for about 20 seconds then die. This was diagnosed a motherboard problem at first but two swaps failed to solve the problem. A new power supply was an inspired guess after a very very long and frustrating session.

The main point about this problem was its tendancy to crash at exactly the same point in the boot sequence. Not possible said our local repair man but after he "recycled" the power supply he was forced to agree,

This is probably a one off but if you are desperate and can swap power supplies it could be worth a try.

Andy Holden

 

[Guest_imported]

reset your bios, you will find the jumpers next to the battery you will see three jumper legs move the jumper lug to the next leg reboot then turn off then replace the jumper the sameway and boot.