PC is a DELL GX270 (service tag 856M11J)
It connects via its Serial port to a PLC (Programmable Logic Controller) which is controlling a desalination process.
512Mb RAM
80Gb Maxtor IDE HD
P4 2.8Ghz
XP Pro 2002 SP1
It has been working fine for at least 10 months and since it was installed it has not been changed in any way (no additional software).
PC is not on a LAN
PC is not connected to the Internet at any time
It is a standalone PC running a single application.
In the last few weeks the PC has been freezing ( the mouse and keyboard will not work/respond).
A hard reboot (power off) is the only way out.
The frequency of the freeze has been increasing to the point where it occurs three or four time a day and each time a hard reboot is required.
The PC is now disconnected from the PLC and is exhibiting the following behaviour.
Each time you reboot the PC you get a different error message (pick from any of the following)
...PAGE_FAULT_IN_NON_PAGED
_AREA...
...Local DLLs needed for HAL...
...IRQL_NOT_LESS_OR_EQUAL.
..
....classpnd.sys...
etc, etc.
There is absolutley no consistent error message and I have tried putting the PC in SAFE mode and DEBUGGING mode but in either case Windows starts and you get a desktop but as soon as you try to do anything the PC shuts down without warning (blackscreen)
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This morning I got the DELL XP CD out and booted from the CD. I started off the OS install and everything was going fine and then the PC halted and went to a BLACKSCREEN with no error message whatsoever. I tried this twice more whilst monitoring the installation messages to see if it was always halting at the same place but each time it was at a different point.
What I call BLACKSCREEN is the equivalent of the power going off (although that is definitely not the case). During the OS re-install, at the point where it stops you actually hear the CD stop spinning!!
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Tests....
I have carried out hardware checks which all report that the Hard Drive is fine.
I have attached the hard drive to another PC and I can see all the data on the drive without any problem.
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Finally, all through this text I have spoken about 1 (one) PC. In actual fact there are another 3 , all displaying very similar behaviour. In all respects they are individual machines and are not physically connected in any way whatsoever (inc WiFi).
Since June 2 when the first PC had problems the other three have also started freezing. The PCs are known as A,BC & D and at this point in time A & D cannot be started at all. If you switch the power on they get as far as the ENTER BIOS screen and as soon as that clears the screen goes blank.
Does any one have any idea what may be happening here ?
