CPU insertion causes system to shut down after a few seconds

  • Thread starter Thread starter Ja
  • Start date Start date
J

Ja

Hi - Celeron 900 seems to be stopping the system from starting - This is an
existing CPU but the system does not power on. I have checked the PSU with
tester and replacement - I have removed everything from the system and my
results are below.

1) With the CPU installed, the system starts up for a second and then dies
2) With CPU taken out, the system turns on and power stays on ( i do not
have a spare CPU to test this with)
3) If however RAM is taken out and CPU left in, then I get the RAM error
BIOS beeps but the system stays powered on

I am thinking still that this is the CPU - but have I miised anything. Your
help would be grateully received as I am trying o take my A+.

regards,
Jack
 
Ja said:
Hi - Celeron 900 seems to be stopping the system from starting - This is an
existing CPU but the system does not power on. I have checked the PSU with
tester and replacement - I have removed everything from the system and my
results are below.

1) With the CPU installed, the system starts up for a second and then dies
2) With CPU taken out, the system turns on and power stays on ( i do not
have a spare CPU to test this with)
3) If however RAM is taken out and CPU left in, then I get the RAM error
BIOS beeps but the system stays powered on

I am thinking still that this is the CPU - but have I miised anything. Your
help would be grateully received as I am trying o take my A+.

regards,
Jack
Click to expand...

P.S - The CPU fan is working all the time -
 
Pen said:
and have you tried it with a different ram stick? or
checked the ram elsewhere?
Click to expand...

Yes I have tried another RAM stick - but the system reacted the same as
before
 
To be frank, I'd suspect a PSU first in this case. CPUs that
function don't draw enough current to do what you describe as
they
usually are dead by then. The same for ram sticks
 
I am no expert, but condition 3 would seem to indicate a memory
problem, or maybe some other component in the POST.

hawk
 
hawk said:
I am no expert, but condition 3 would seem to indicate a memory
problem, or maybe some other component in the POST.

hawk
Click to expand...

I did try another working RAM stick and I try another PSU - thanks for all
your help - what else could it be - all cards where removed. (onboard
graphics)
 
Pen said:
To be frank, I'd suspect a PSU first in this case. CPUs that
function don't draw enough current to do what you describe as
they
usually are dead by then. The same for ram sticks
Click to expand...

Someone installed a modem a few weeks ago - could this have somehow damaged
the motherboard to cause this ?
 
Well, the CPU stays powered when there is no memory. You get an error
and the POST stops. It could be the next step in the POST that causes
the problem. Is the battery that maintains power to the CMOS OK?

hawk
 
hawk said:
Well, the CPU stays powered when there is no memory. You get an error
and the POST stops. It could be the next step in the POST that causes
the problem. Is the battery that maintains power to the CMOS OK?

hawk
Click to expand...

Yes the bios battery is reading correctly - how would that cause it - is the
next step in POST. If the cpu is one of the first things to get checked
(before RAM?) on post then what would happen if the post did not find a
cpu -
 
Ja said:
Yes the bios battery is reading correctly - how would that cause it -
is the next step in POST. If the cpu is one of the first things to
get checked (before RAM?) on post then what would happen if the post
did not find a
cpu -
Click to expand...

I had symptoms described in the original post (result 1) but with an AMD
XP 2400 processor. Would come on and then just shut off again after a
little variable while.

Nothing I tried worked. I put new memory in, a new processor, even
bought an entire new case for the 300w PSU it came with (as it was a
desktop unit with one of those mini PSU units). Still did the same
thing so it wasn't a component issue, nor was the original PSU at fault.

So then I took the heatsink off, cleaned off the thermal pad on the
underside of the heatsink and replaced it with a new pad. Put the
heatsink back, fire it up. Problem solved.

Hope this helps :)
 
Hello Ja, Neil is exactly right on. I have had this happen many times with
an AMD. If the heat from the CPU is not disippated immediately the system
will shut down. Just remove the heat sink and carefully clean all the
thermal paste from the CPU and the heat sink and reassemble them. Make sure
the heat sink is applied flat against the CPU. That should do it. Hope this
helps.
 
Ja said:
Hi - Celeron 900 seems to be stopping the system from starting - This is an
existing CPU but the system does not power on. I have checked the PSU with
tester and replacement - I have removed everything from the system and my
results are below.

1) With the CPU installed, the system starts up for a second and then dies
2) With CPU taken out, the system turns on and power stays on ( i do not
have a spare CPU to test this with)
3) If however RAM is taken out and CPU left in, then I get the RAM error
BIOS beeps but the system stays powered on

I am thinking still that this is the CPU - but have I miised anything. Your
help would be grateully received as I am trying o take my A+.

regards,
Jack
Click to expand...
Hi - everyone who is helping - I tried some thermal paste- but still same as
before - HELP! - thanks
 
Hi - everyone who is helping - I tried some thermal paste- but still same as
before - HELP! - thanks
Click to expand...


I fried a CPU and when I turned the comp on all the fans would come on,
the LEDS on the front would light up, but nothing else. So either that's
happened, or your heatsink is fubar and it's overheating in 2 seconds.
 
reset the cmos. pull the plug and pull the battery or short the
jumper. Have you tried a different CPU?
 
JAD said:
reset the cmos. pull the plug and pull the battery or short the
jumper. Have you tried a different CPU?
Click to expand...

Hi - thanks for your help - I tried a new cpu but still the same problem? -
I tried resetting the cmos - is the motherboard dead?

thank you very much for your time
Ja
 
Have you ever checked the power supply outputs?
Are they in spec, when the machine runs? what is
dropping out? The clue here is that a ram stick is
causing the same problem as a CPU.
If not you should.
 
Pen said:
Have you ever checked the power supply outputs?
Are they in spec, when the machine runs? what is
dropping out? The clue here is that a ram stick is
causing the same problem as a CPU.
If not you should.
Click to expand...

I have tried another stick of ram and another PSU - both with same effects
as first post - thanks
 
Unless you do what I said, you will continue to fly blind.
Your only recourse will be wholesale parts replacement,
which is expensive and counterproductive. Get hold of a
digital meter and look at what is actually happening.
Substituting
another power supply told you zero. What is really significant is
that pulling a ram stick allows operation. If you can't/won't do
this then your only other option is to try a new mobo.
 
Pen said:
Unless you do what I said, you will continue to fly blind.
Your only recourse will be wholesale parts replacement,
which is expensive and counterproductive. Get hold of a
digital meter and look at what is actually happening.
Substituting
another power supply told you zero. What is really significant is
that pulling a ram stick allows operation. If you can't/won't do
this then your only other option is to try a new mobo.
Click to expand...


I cannot test this system until tommorrow - and I need to find a
comprehensive method of testing it first - The A+ course does not teach this
sort of thing - Does not replacing the PSU tell me it is not the PSU? - If I
test the PSU outputs - which PSU do I test? - If the PSU reads wrong - will
both PSU's be dodgy? - If the PSU reads right then - I understand what you
say about the RAM causing the same, but would this no then point to the
mobo? - Because I only have an hour to remedy this situation and need to use
the quickest and cost effective method of resolution. Would I be better to
replace the mobo and the cpu? - I hope you can help - thanks.

Ja
 
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