Damaged CPU?

gouche

Hey

I was cleaning out the inside of an old computer today, shocking amount of dirt and dust had built up in and around the fan and heatsink.
I unmounted the processor (P4) and heatsink so I could get all the crap and took out other components to try clear all dust and dirt. But when I reassembled the computer wouldn't turn on.
I checked all connections and made sure I had put the processor and everything else back in right but still no go.
There is a little led on the motherboard where the psu connects to it that lights up when comp is plugged in but when I press button on front of tower nothing happens.

Any idea what it could be? I'm guessing it's not the psu as the board is still getting power but I don't know :pac:

challengemaster

What did you use to clean it out? Sounds like you might have fried the motherboard...

Are there any beeps when you try to power on the PC?

gouche

challengemaster wrote: »

What did you use to clean it out? Sounds like you might have fried the motherboard...

Are there any beeps when you try to power on the PC?

Compressed air. Tried my best not to touch anything, wasn't wearing an anti-static wristband.
No beeps. Absolutely nothing happens when I press the button, no beeps whirrs or lights of any description.

Snowbat

Just to rule out the obvious, can you verify that the power switch connector is pushed fully down on the motherboard pins?

Nothingbetter2d

first b4 u turn it on..... did u take the heatsink off the cpu? if so did u put a clean layer of thermal paste on the cpu b4 putting back on the heatsink and fan?

as i have discovered many motherboards are finicky when u unplug bits from them. as a rule unplug your power cable and wait til those lil led's on the motherboard go off. then plug it back in and turn it on.

gouche

Snowbat wrote: »

Just to rule out the obvious, can you verify that the power switch connector is pushed fully down on the motherboard pins?

The powerswitch is connected to a front panel with USB ports and headphone jack. This gets its power from the motherboard via the USB cable (I think). There's only two wires coming from it, and audio cable for the headphone jack and USB cable for the USB ports. None of these were removed and have since been checked to make sure they're in right.

Nothingbetter2d wrote: »

first b4 u turn it on..... did u take the heatsink off the cpu? if so did u put a clean layer of thermal paste on the cpu b4 putting back on the heatsink and fan?

as i have discovered many motherboards are finicky when u unplug bits from them. as a rule unplug your power cable and wait til those lil led's on the motherboard go off. then plug it back in and turn it on.

Didn't take the heatsink off as didn't have any thermal paste to hand.

ART6

gouche wrote: »

Hey

I was cleaning out the inside of an old computer today, shocking amount of dirt and dust had built up in and around the fan and heatsink.
I unmounted the processor (P4) and heatsink so I could get all the crap and took out other components to try clear all dust and dirt. But when I reassembled the computer wouldn't turn on.
I checked all connections and made sure I had put the processor and everything else back in right but still no go.
There is a little led on the motherboard where the psu connects to it that lights up when comp is plugged in but when I press button on front of tower nothing happens.

Any idea what it could be? I'm guessing it's not the psu as the board is still getting power but I don't know :pac:

I managed to do that once with a compressed air can when I was in a hurry and hadn't put my brain into gear before I pressed the can button. I directed the jet at the chip cooling fan without thinking, and it spun it at high speed. DC motors if driven act as generators, and my actions caused a voltage to flow back through a system where it was only supposed to go one way! I was luck in a sense in that it only fried the peripherals -- CD drive etc. However, I learned my lesson and whenever I use a compressed air can I hold the fan blades still!

Having given that bit of useless information I have no idea what might have happened to your machine or how to deal with it, but I would fear the worst! Those compressed air cans should come with a safety warning!

gouche

ART6 wrote: »

I managed to do that once with a compressed air can when I was in a hurry and hadn't put my brain into gear before I pressed the can button. I directed the jet at the chip cooling fan without thinking, and it spun it at high speed. DC motors if driven act as generators, and my actions caused a voltage to flow back through a system where it was only supposed to go one way! I was luck in a sense in that it only fried the peripherals -- CD drive etc. However, I learned my lesson and whenever I use a compressed air can I hold the fan blades still!

Having given that bit of useless information I have no idea what might have happened to your machine or how to deal with it, but I would fear the worst! Those compressed air cans should come with a safety warning!

I had disconnected the fan before cleaning, had to move away from the computer cause there was so much crap after building up on it I was afraid I'd blow it all onto the motherboard!

CrinkElite

I really doubt you've done any damage if you were as careful as you say you were. my advise would be to disconnect everything and start putting it back together again.

Overheal

did you try to reset the CMOS?

BostonB

CrinkElite wrote: »

I really doubt you've done any damage if you were as careful as you say you were. my advise would be to disconnect everything and start putting it back together again.

+1

That said sometimes old machines just don't like being disturbed.

gouche

CrinkElite wrote: »

I really doubt you've done any damage if you were as careful as you say you were. my advise would be to disconnect everything and start putting it back together again.

Yeah, I'll have another look over it today, there must be something I missed!

Overheal wrote: »

did you try to reset the CMOS?

I've taken the CMOS out and replaced it after a few minutes. I've also moved the jumper - all to no avail.

Keywal

ha!

i did this before... last week in fact! of course the customer wasn't best pleased but i fixed it in the end..


you say you disconnected everything and the test led comes on so we know the PSU is fine. your then pushing the power button on the case right?

when i did this i accidently removed the ribbon that leads from the power button to the board!!!! everything was plugged in, looked ok and i was scratching my head for ages! the problem was that the power button was housed in a big plastic casing so was hard to get to but got there in the end!

gouche

Keywal wrote: »

ha!

i did this before... last week in fact! of course the customer wasn't best pleased but i fixed it in the end..


you say you disconnected everything and the test led comes on so we know the PSU is fine. your then pushing the power button on the case right?

when i did this i accidently removed the ribbon that leads from the power button to the board!!!! everything was plugged in, looked ok and i was scratching my head for ages! the problem was that the power button was housed in a big plastic casing so was hard to get to but got there in the end!

I thought this might be my problem. After a LOT of hard work getting the front cover off (damn you Dell!) turns out that wasn't my problem at all. Everything seems fine with regard to the power button.

I really am at a loss as to what's wrong now

Keywal

the machine i was trying to clean was a Dell too!

i think its time to start looking into mobo failure!

were you in any way rough taking cables out?
did you drop it or catch it on anything?

you'll have to start trouble shooting with more parts. get a mobo from somewhere and test if it spins up.

take out the ram and see will it start with out it.
try every possible combination of taking parts out. in the end from reading what has been said before the board is gone to hardware heaven.

Nothingbetter2d

check that u didn't accidentally break off a capacitor on the motherboard. if u did then u have 2 options

1. find someone qualified in electronics/electrician to solder it back on

2. get a new motherboard

Overheal

gouche wrote: »

Yeah, I'll have another look over it today, there must be something I missed!



I've taken the CMOS out and replaced it after a few minutes. I've also moved the jumper - all to no avail.

did you remove the jumper or did you place it in the reset position with the battery inserted?

gouche

Nothingbetter2d wrote: »

check that u didn't accidentally break off a capacitor on the motherboard. if u did then u have 2 options

1. find someone qualified in electronics/electrician to solder it back on

2. get a new motherboard

Checked the capacitors, none broken.

Overheal wrote: »

did you remove the jumper or did you place it in the reset position with the battery inserted?

Placed it in the reset position. I also tried just removing the battery for a minute or two and trying it but none worked.

I have another computer so I'm going to try what components I can in that to see if I can eliminate them and find the source of the problem.

Overheal

and you didnt break any pins on the CPU or anything?

BostonB

I hate going near old machines that have been untouched for years. a lot of them just die if messed with at all. Maybe its the spike/surge when being rebooted for the first time in years. Maybe it kills the boards.

Overheal

BostonB wrote: »

I hate going near old machines that have been untouched for years. a lot of them just die if messed with at all. Maybe its the spike/surge when being rebooted for the first time in years. Maybe it kills the boards.

it could have died a long time ago from static buildup from weather reasons, or being fiddled with when it was covered with dust: the same kind of reasons why rugs, when not grounded to anything, will charge you up. hard to say. Either way unless there was to be some overclocking going on, this old machine wouldnt be worth all that much, it would be barely able to handle most programs, from my experience. the internet in particular is very graphics heavy these days and without a semi-modern IGP (even one of those Intel ones that you shouldnt game on) your PC will struggle to render pages while doing anything else. They pre-date modern Flash and emerging HTML5. Let alone the demands of Antivirus and Internet Security that have only increased in the last 10 years. forget multitasking. Its not that the machine is slower but the content of today is far more demanding. and arguably not as optimized.

I could only see using an Old PC as an offline child's homework PC or a music player. Possibly a makeshift home network server, but thats a damn stretch.

BostonB

How do you know what kinda machine this is? While a low end P4 is too slow. A higher end one with enough RAM is ok for web stuff.

I've found even the low end ones are ok, without AV on them. But the latest AV just cripple them. Over the last year or two the AV solutions have become very demanding.

gouche

Overheal wrote: »

it could have died a long time ago from static buildup from weather reasons, or being fiddled with when it was covered with dust: the same kind of reasons why rugs, when not grounded to anything, will charge you up. hard to say. Either way unless there was to be some overclocking going on, this old machine wouldnt be worth all that much, it would be barely able to handle most programs, from my experience. the internet in particular is very graphics heavy these days and without a semi-modern IGP (even one of those Intel ones that you shouldnt game on) your PC will struggle to render pages while doing anything else. They pre-date modern Flash and emerging HTML5. Let alone the demands of Antivirus and Internet Security that have only increased in the last 10 years. forget multitasking. Its not that the machine is slower but the content of today is far more demanding. and arguably not as optimized.

I could only see using an Old PC as an offline child's homework PC or a music player. Possibly a makeshift home network server, but thats a damn stretch.

As I've stated previously, the computer was in perfect working order after a clean install. It stopped working after the clean-out. While the PC was quite old, it was still more than capable of rendering the vast majority of web pages. It has an older nVidia card (forget the model) with 256mb of vram. Not a lot but still more than enough to easily render all but the most demanding of web pages. I remember playing Half-Life 2 on this machine when it first came out.

Keywal

How's the trouble shooting going with different parts?

Overheal

gouche wrote: »

As I've stated previously, the computer was in perfect working order after a clean install. It stopped working after the clean-out. While the PC was quite old, it was still more than capable of rendering the vast majority of web pages. It has an older nVidia card (forget the model) with 256mb of vram. Not a lot but still more than enough to easily render all but the most demanding of web pages. I remember playing Half-Life 2 on this machine when it first came out.

not as old as im thinking then.