A computer components & hardware forum. HardwareBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » HardwareBanter forum » General Hardware & Peripherals » General
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

PC hangs with cover on, doesnt hang with cover off! bizarre



 
 
Thread Tools Display Modes
  #1  
Old March 1st 04, 03:03 PM
Colm Ward
external usenet poster
 
Posts: n/a
Default PC hangs with cover on, doesnt hang with cover off! bizarre

Hi

I have a bizarre problem with an old (but still useful) Dell Optiplex
which I've been given. It's a 166MHz with 128MB RAM.

If I boot (Win NT), after something between 2 and 25 minutes the
machine will hang and wont boot up again at all until I switch it off
and give it maybe half an hour to "recover".

If I take the cover off (horizontal case, not tower), the machine will
boot and run fine with no problem. But the instant I replace the
cover, before the cover is even fully on, the system hangs as before.
This has happened several times, there is no way that it is a
coincidence.

Have tried reseating all the cards and memory, formatting HDD and
reinstalling, scanning for hard disk errors. The processor is old
enough not to need a fan so thats not an issue.

Any ideas at all would be most appreciated. Thanks a million
-Colm
  #2  
Old March 1st 04, 03:41 PM
Alien Zord
external usenet poster
 
Posts: n/a
Default

"Colm Ward" wrote in message
om...
Hi

I have a bizarre problem with an old (but still useful) Dell Optiplex
which I've been given. It's a 166MHz with 128MB RAM.

If I boot (Win NT), after something between 2 and 25 minutes the
machine will hang and wont boot up again at all until I switch it off
and give it maybe half an hour to "recover".

If I take the cover off (horizontal case, not tower), the machine will
boot and run fine with no problem. But the instant I replace the
cover, before the cover is even fully on, the system hangs as before.
This has happened several times, there is no way that it is a
coincidence.

Have tried reseating all the cards and memory, formatting HDD and
reinstalling, scanning for hard disk errors. The processor is old
enough not to need a fan so thats not an issue.

Any ideas at all would be most appreciated. Thanks a million
-Colm


PSU fan not spinning any more?


  #3  
Old March 1st 04, 04:54 PM
SpongeBob
external usenet poster
 
Posts: n/a
Default


"Alien Zord" wrote in message
...
"Colm Ward" wrote in message
om...
Hi

I have a bizarre problem with an old (but still useful) Dell Optiplex
which I've been given. It's a 166MHz with 128MB RAM.

If I boot (Win NT), after something between 2 and 25 minutes the
machine will hang and wont boot up again at all until I switch it off
and give it maybe half an hour to "recover".

If I take the cover off (horizontal case, not tower), the machine will
boot and run fine with no problem. But the instant I replace the
cover, before the cover is even fully on, the system hangs as before.
This has happened several times, there is no way that it is a
coincidence.

Have tried reseating all the cards and memory, formatting HDD and
reinstalling, scanning for hard disk errors. The processor is old
enough not to need a fan so thats not an issue.

Any ideas at all would be most appreciated. Thanks a million
-Colm


PSU fan not spinning any more?



Sounds like the cover (case) is shorting on something...pinching/touching a
wire, cable, etc...


  #4  
Old March 2nd 04, 12:42 AM
DaveW
external usenet poster
 
Posts: n/a
Default

It sounds like a thermal overheating issue. With the cover off, and the
additional cooling from being open, it doesn't hang.

--
DaveW



"Colm Ward" wrote in message
om...
Hi

I have a bizarre problem with an old (but still useful) Dell Optiplex
which I've been given. It's a 166MHz with 128MB RAM.

If I boot (Win NT), after something between 2 and 25 minutes the
machine will hang and wont boot up again at all until I switch it off
and give it maybe half an hour to "recover".

If I take the cover off (horizontal case, not tower), the machine will
boot and run fine with no problem. But the instant I replace the
cover, before the cover is even fully on, the system hangs as before.
This has happened several times, there is no way that it is a
coincidence.

Have tried reseating all the cards and memory, formatting HDD and
reinstalling, scanning for hard disk errors. The processor is old
enough not to need a fan so thats not an issue.

Any ideas at all would be most appreciated. Thanks a million
-Colm



  #5  
Old March 2nd 04, 03:31 AM
~misfit~
external usenet poster
 
Posts: n/a
Default

Alien Zord wrote:
"Colm Ward" wrote in message
om...
Hi

I have a bizarre problem with an old (but still useful) Dell Optiplex
which I've been given. It's a 166MHz with 128MB RAM.

If I boot (Win NT), after something between 2 and 25 minutes the
machine will hang and wont boot up again at all until I switch it off
and give it maybe half an hour to "recover".

If I take the cover off (horizontal case, not tower), the machine
will boot and run fine with no problem. But the instant I replace the
cover, before the cover is even fully on, the system hangs as before.
This has happened several times, there is no way that it is a
coincidence.

Have tried reseating all the cards and memory, formatting HDD and
reinstalling, scanning for hard disk errors. The processor is old
enough not to need a fan so thats not an issue.

Any ideas at all would be most appreciated. Thanks a million
-Colm


PSU fan not spinning any more?


I think the two salient points here a

A, It's a Dell

B, He said "But the instant I replace the cover, before the cover is even
fully on"

Some proprietry machines, including Dell, if memory serves, may have a
"Chassis Intrusion detection switch". I think this *may* be the problem.
Sometimes thay can be disabled from the BIOS, or maybe just checking if it
has such a switch and either taping it down or disconnecting it.

I could be wrong, but that's my first thought. Switch malfunction.

And, to the OP, does that machine have a bloody great big Dell heatsink that
sits in the airflow intake for the PSU? If it does (that's what they had
originally) you're right, it doesn't need a CPU fan as long as the PSU fan
is still going strong. If however the CPU heatsink has been replaced then it
*will* benefit from a fan. The Dell P1 HS I have here has two spring-steel
'leaves' attached to it (for want of a better word) that seem to have been
designed to contact the PSU and the case-lid. (I don't know if that's
relevant or not). It's also a big thing, about as big as a coffee cup
(although a different shape of course).
--
~misfit~


  #6  
Old March 2nd 04, 09:44 AM
Alien Zord
external usenet poster
 
Posts: n/a
Default

"~misfit~" wrote in message
...
Alien Zord wrote:
"Colm Ward" wrote in message
om...
If I boot (Win NT), after something between 2 and 25 minutes the
machine will hang and wont boot up again at all until I switch it off
and give it maybe half an hour to "recover".

If I take the cover off (horizontal case, not tower), the machine
will boot and run fine with no problem. But the instant I replace the
cover, before the cover is even fully on, the system hangs as before.
This has happened several times, there is no way that it is a
coincidence.


PSU fan not spinning any more?


I think the two salient points here a

A, It's a Dell

B, He said "But the instant I replace the cover, before the cover is even
fully on"


1) I noticed it and chose to disregard it because you and I can take 5
seconds to put a cover on but a complete layman can take minutes especially
on a Dell some of which can be really awkward. With the cover off the
machine might be running at a temp just bellow which a component causes
electrical latch-up. Put the cover on and the temp will rise rapidly
bringing on the fault.

2) If the OP boots the machine from cold with the cover on it will run for 2
to 20 mins ruling out a cover switch.

3) The fact that the machine will boot again after being off for half an
hour suggests its a thermal issue and due to its age PSU fan failure is
quite a possibility.


  #7  
Old March 2nd 04, 12:11 PM
~misfit~
external usenet poster
 
Posts: n/a
Default

Alien Zord wrote:
"~misfit~" wrote in message
...
Alien Zord wrote:
"Colm Ward" wrote in message
om...
If I boot (Win NT), after something between 2 and 25 minutes the
machine will hang and wont boot up again at all until I switch it
off and give it maybe half an hour to "recover".

If I take the cover off (horizontal case, not tower), the machine
will boot and run fine with no problem. But the instant I replace
the cover, before the cover is even fully on, the system hangs as
before. This has happened several times, there is no way that it
is a coincidence.


PSU fan not spinning any more?


I think the two salient points here a

A, It's a Dell

B, He said "But the instant I replace the cover, before the cover is
even fully on"


1) I noticed it and chose to disregard it because you and I can take 5
seconds to put a cover on but a complete layman can take minutes
especially on a Dell some of which can be really awkward. With the
cover off the machine might be running at a temp just bellow which a
component causes electrical latch-up. Put the cover on and the temp
will rise rapidly bringing on the fault.

2) If the OP boots the machine from cold with the cover on it will
run for 2 to 20 mins ruling out a cover switch.

3) The fact that the machine will boot again after being off for half
an hour suggests its a thermal issue and due to its age PSU fan
failure is quite a possibility.


Yep, all good points. I was just throwing something else into the mix. That
bit about the thing failing before he's got the cover on properly just made
me think about those switches.

You're right, I'd look at the PSU fan first. I just thought that was a bit
obvious. I do have a tendancy to think that certain procedure has been
followed before asking for help. Bad habit of mine.
--
~misfit~


  #8  
Old March 2nd 04, 02:44 PM
SpongeBob
external usenet poster
 
Posts: n/a
Default


"DaveW" wrote in message
news:RTP0c.159739$uV3.707467@attbi_s51...
It sounds like a thermal overheating issue. With the cover off, and the
additional cooling from being open, it doesn't hang.

--
DaveW



"Colm Ward" wrote in message
om...
Hi

I have a bizarre problem with an old (but still useful) Dell Optiplex
which I've been given. It's a 166MHz with 128MB RAM.

If I boot (Win NT), after something between 2 and 25 minutes the
machine will hang and wont boot up again at all until I switch it off
and give it maybe half an hour to "recover".

If I take the cover off (horizontal case, not tower), the machine will
boot and run fine with no problem. But the instant I replace the
cover, before the cover is even fully on, the system hangs as before.
This has happened several times, there is no way that it is a
coincidence.

Have tried reseating all the cards and memory, formatting HDD and
reinstalling, scanning for hard disk errors. The processor is old
enough not to need a fan so thats not an issue.

Any ideas at all would be most appreciated. Thanks a million
-Colm




Then why would it hang "the instant" he puts the cover back on...Case Short
Circuiting...IMHO.


  #9  
Old March 2nd 04, 07:16 PM
Colm Ward
external usenet poster
 
Posts: n/a
Default

Hi

Thanks a lot for all your very helpful replies.

The PSU fan is spinning although the PSU unit in general is well
dusty.

Its not a wire getting pinched by the cover as there is nothing in the
slots for the case except some metal clips which I presume are for the
case lid to make conductive contact with the base chassis.

Also I couldnt find anything resembling a switch around the edges and
there is no mention of intrusion detection in the BIOS.

It takes me about 10 seconds to put the cover back on. The machine can
hang anytime from when I start to lower the case onto the base
chassis, to the last push to click it into place.

My own feelings were that it was a thermal issue, well either that or
it had to be some kind of electromagnetic thing as the machine seemed
to 'sense' the approach of the cover sometimes.

So I'm wondering if I should replace the PSU, or maybe install another
fan somewhere. I did try putting a spare fan beside the processor at
one point, I think the machine stayed running for slightly longer but
it still froze up in the end (the cover was on at that point).

What would be the best place to install an extra fan - beside the
processor or beside the memory? The processor does have a big green
heat sink but it does not make contact with the case lid. It's
situated at the opposite corner of the chassis from the PSU so I don't
know if you could say that it is in the airflow of the PSU fan.

Also should a fan blow or suck air over the thing it's supposed to
cool? Does direction of airflow matter?

thanks again
-Colm





"DaveW" wrote in message news:RTP0c.159739$uV3.707467@attbi_s51...
It sounds like a thermal overheating issue. With the cover off, and the
additional cooling from being open, it doesn't hang.

--
DaveW



"Colm Ward" wrote in message
om...
Hi

I have a bizarre problem with an old (but still useful) Dell Optiplex
which I've been given. It's a 166MHz with 128MB RAM.

If I boot (Win NT), after something between 2 and 25 minutes the
machine will hang and wont boot up again at all until I switch it off
and give it maybe half an hour to "recover".

If I take the cover off (horizontal case, not tower), the machine will
boot and run fine with no problem. But the instant I replace the
cover, before the cover is even fully on, the system hangs as before.
This has happened several times, there is no way that it is a
coincidence.

Have tried reseating all the cards and memory, formatting HDD and
reinstalling, scanning for hard disk errors. The processor is old
enough not to need a fan so thats not an issue.

Any ideas at all would be most appreciated. Thanks a million
-Colm

  #10  
Old March 2nd 04, 07:34 PM
SpongeBob
external usenet poster
 
Posts: n/a
Default


"Colm Ward" wrote in message
om...
Hi

Thanks a lot for all your very helpful replies.

The PSU fan is spinning although the PSU unit in general is well
dusty.

Its not a wire getting pinched by the cover as there is nothing in the
slots for the case except some metal clips which I presume are for the
case lid to make conductive contact with the base chassis.

Also I couldnt find anything resembling a switch around the edges and
there is no mention of intrusion detection in the BIOS.

It takes me about 10 seconds to put the cover back on. The machine can
hang anytime from when I start to lower the case onto the base
chassis, to the last push to click it into place.

My own feelings were that it was a thermal issue, well either that or
it had to be some kind of electromagnetic thing as the machine seemed
to 'sense' the approach of the cover sometimes.

So I'm wondering if I should replace the PSU, or maybe install another
fan somewhere. I did try putting a spare fan beside the processor at
one point, I think the machine stayed running for slightly longer but
it still froze up in the end (the cover was on at that point).

What would be the best place to install an extra fan - beside the
processor or beside the memory? The processor does have a big green
heat sink but it does not make contact with the case lid. It's
situated at the opposite corner of the chassis from the PSU so I don't
know if you could say that it is in the airflow of the PSU fan.

Also should a fan blow or suck air over the thing it's supposed to
cool? Does direction of airflow matter?

thanks again
-Colm





"DaveW" wrote in message

news:RTP0c.159739$uV3.707467@attbi_s51...
It sounds like a thermal overheating issue. With the cover off, and the
additional cooling from being open, it doesn't hang.

--
DaveW



"Colm Ward" wrote in message
om...
Hi

I have a bizarre problem with an old (but still useful) Dell Optiplex
which I've been given. It's a 166MHz with 128MB RAM.

If I boot (Win NT), after something between 2 and 25 minutes the
machine will hang and wont boot up again at all until I switch it off
and give it maybe half an hour to "recover".

If I take the cover off (horizontal case, not tower), the machine will
boot and run fine with no problem. But the instant I replace the
cover, before the cover is even fully on, the system hangs as before.
This has happened several times, there is no way that it is a
coincidence.

Have tried reseating all the cards and memory, formatting HDD and
reinstalling, scanning for hard disk errors. The processor is old
enough not to need a fan so thats not an issue.

Any ideas at all would be most appreciated. Thanks a million
-Colm


Well...without getting really small and climbing into the unit
itself...while you put the cover on...I can't be positive, but your symptoms
are that of shorting out. I don't think any component in there would go from
ambient temperatures to overheating in less than 10 seconds...Unless you
used a blow torch of course. Often when closing those bulky covers, things
shift slightly...especially if they are not tight. Slight movement of the
motherboard could cause it to short off the case or some adjacent component
touching it. Loose standoff's could create a "shorting" issue...or possibly
a screw that has fallen between the motherboard and case...Anyway these
"instant lockups" due to physical movement of parts are almost always due to
something touching what it shouldn't. My 4 cents now I guess...


 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Frequent hang! philo General 4 October 10th 06 12:11 PM
FIC or HIS for a 9600Pro? Phrederick General 8 December 16th 03 01:17 PM
New PC hangs for no apparent reason Prizm General 8 October 21st 03 07:05 PM
Random hangs on KT133 and KT333 with raid kony General 5 September 15th 03 09:46 AM


All times are GMT +1. The time now is 03:06 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 HardwareBanter.
The comments are property of their posters.