Bootup problems

[B16 RFF]

I need to pick PHs' collective brain !!

I have a DEll 2350 about 4 years old.
A couple of weeks ago, the main CPU cooling fan packed up, which is par for the course I believe. I took the cover off the machine to see if there was anything obviously wrong. Apart from a lot of dust, all seemed OK. I powered up the machine, and it ran for a couple of minutes before it shut itself down. After a few seconds, it tried to start up again. A couple of seconds later, it shuts down again. It just continues to cycle like this, never getting more than a couple of seconds into the bootup before shutting down again. Nothing appears on the screen.
I have tried swapping first the motherboard and then the PSU with known good ones, but the fault is always there. Have I fried the CPU? Surely it would shut itself down before any damage could occur ?

Any thoughts would be appreciated.

BTW, it's not the hard drive, as a friend has powered it up and extracted data to be transferred to a new PC.

Paul.

[spitfire-ian]

You have replaced the fan that failed haven't you????

[B16 RFF]

spitfire-ian said:

You have replaced the fan that failed haven't you????

Yes,sorry, forgot to mention that.

[ErnestM]

CPU's TRY to shut themselves down before damage. They don't always succeed. I managed to kill a Pentium Extreme 840 last October (hence my absence for a while) by some not very smart OC attempts. It had similar symptoms to what you are describing. I swapped out the lot. Graphics card, motherboard, RAM, PSU. When I replaced the 840 with a Pentium D into the original hardware, it came up and ran fine (in fact is still running fine. I'm using the system as a network renderer for 3ds Max now)

ErnestM

[ThePassenger]

Depeds on the chip/mobo. It might have not shut down in time.
Is the fan you fitted a 3pin or a 2pin jobbie? A lot of motherboards default to checking the CPU fan speed and if it reads 0 they shut down.

Try removing every add-in card and external connection, (yank the HDD/DVD/Floppy cables out the mobo). Power it up, if it hangs around you know something else is banjoed.

[B16 RFF]

ThePassenger said:

Depeds on the chip/mobo. It might have not shut down in time.
Is the fan you fitted a 3pin or a 2pin jobbie? A lot of motherboards default to checking the CPU fan speed and if it reads 0 they shut down.

Try removing every add-in card and external connection, (yank the HDD/DVD/Floppy cables out the mobo). Power it up, if it hangs around you know something else is banjoed.

Its a celeron chip on a Dell socket 478 motherboard. Fan is 3 pin type and is now new (but not Dell supplied). Tried the business of disconnecting CD drives etc., but no joy.

Thanks ErnestM. I will look around for a cheap replacement CPU. I believe a Pentium4 will physically fit, but will it work Ok with this motherboard?

If that doesn't work, the dustbin beckons....

Edited by B16 RFF on Wednesday 9th May 17:08

[ThePassenger]

Fair enough.

Yes, a P4 with the same pinout will fit on that board and will work. I would aim for a P4 without HT (i.e. one of the first generation) and you'll be fine.

[B16 RFF]

ThePassenger said:

Fair enough.

Yes, a P4 with the same pinout will fit on that board and will work. I would aim for a P4 without HT (i.e. one of the first generation) and you'll be fine.

Thanks.

[ErnestM]

B16 RFF said:

ThePassenger said:

Depeds on the chip/mobo. It might have not shut down in time.
Is the fan you fitted a 3pin or a 2pin jobbie? A lot of motherboards default to checking the CPU fan speed and if it reads 0 they shut down.

Try removing every add-in card and external connection, (yank the HDD/DVD/Floppy cables out the mobo). Power it up, if it hangs around you know something else is banjoed.

Its a celeron chip on a Dell socket 478 motherboard. Fan is 3 pin type and is now new (but not Dell supplied). Tried the business of disconnecting CD drives etc., but no joy.

Thanks ErnestM. I will look around for a cheap replacement CPU. I believe a Pentium4 will physically fit, but will it work Ok with this motherboard?

If that doesn't work, the dustbin beckons....

I always check out the motherboard at the manufacturer's web site before I replace a cpu. However, as you have a Dell, that may not be possible. It all depends which "customer service" rep you get at Dell. Do you have any idea what chipset it is running?

ErnestM

[ThePassenger]

It'll be an Intel chipset.

[B16 RFF]

ErnestM said:

I always check out the motherboard at the manufacturer's web site before I replace a cpu. However, as you have a Dell, that may not be possible. It all depends which "customer service" rep you get at Dell. Do you have any idea what chipset it is running?

ErnestM

Its Intel 845GL according to the on-line motherboard manual.
According to the same document, the system clock is 400 MHz. Presumably I will have to find a CPU suitable for that clock speed, but I can use a faster chip - current one is 1.8 Ghz?
Also is the system clock speed the same thing as the FSB clock speed?

Thanks for your help.

Paul.

[ErnestM]

B16 RFF said:

ErnestM said:

I always check out the motherboard at the manufacturer's web site before I replace a cpu. However, as you have a Dell, that may not be possible. It all depends which "customer service" rep you get at Dell. Do you have any idea what chipset it is running?

ErnestM

Its Intel 845GL according to the on-line motherboard manual.
According to the same document, the system clock is 400 MHz. Presumably I will have to find a CPU suitable for that clock speed, but I can use a faster chip - current one is 1.8 Ghz?
Also is the system clock speed the same thing as the FSB clock speed?

Thanks for your help.

Paul.

Just make sure that you get the 478 pin P4 for this chipset...

ErnestM