I've got an HP/Compaq NC6000. The comp runs fine for awhile, but when it heats up, it seems to lock up. A reboot causes random read errors or NTLDR missing errors. I suspected a bad hard drive, so I swapped with a good running hard drive and a ghosted image of the first drive, only it will not boot from said good drive. It says "error loading disk, press ctrl-alt-delete". I tried to do a blank install of windows XP, but halfway through loading the OS, it gets to the 34mins remaining screen and it just stays there. The computer does not freeze up, but it sits at that screen playing the various windows animations and scroll bars indefinately.

I swapped in extra ram and tried to boot a bootable linux CD-rom, which boots but it takes and EXTREMELY long time to boot. I tried booting a bootable windows MINpe disk, and it also loads but it takes awhile to do so. Finally, I swapped in a known, working optical drive and tried all again with the same results.

So to sum this up, swapped in new hard drive, new ram and new optical drive with the same faults.

What else could it be? Bad motherboard? bad processor? Bad fan? Whenever the laptop runs for more than a few minutes and heats up, things grind to a hault. It sat on the windows installation screen for 11 hours with no progress.

Often, those HP and Compaq models are fine for everyday use, but when you add devices and workload, you need a more resilient power supply... not so much more watts, but more amps per rail.
You might want to borrow one from another machine to test.

it can be southbridge faulty.

Extremely unlikely in that laptop.

raybay, do you know, that the 82801dbm bridges dies in many laptops, and it's independent of the manufacturer? and from the other side, in this laptop, the HDD connects directly to southbridge without any buffering chips. thus, if HDD shows errors during reading and writing, it can be some disturbances in the primary/secondary IDE channels IN THE SOUTHBRIDGE CHIP.

I understand, but we have torn up and repaired hundreds of Compaq 2500 series, and almost never see this problem... perhaps once, and that was due to meddling of the user.

On the other hand, are you aware there are 434 models of the Compaq Presario 2500 series of laptops... and most failures are simple hard drive crashes caused by lateral impact by the user.

well, i guess, we speak now about nc6000
and don't forget, a huge variety of models presario 2500, but still one basical mobo

Exactly my point. Same motherboard. Huge numbers out there. No Southbridge errors.

Hi, I too have a HP nc6000 which has just started to freeze/lockup the only way to get it going again is to switch off then on again, this doesn't always work first time but it does work eventually, I tried the HP on line diagnostics which suggested a problem with the hard drive, so I installed a new one but, low and behold the same thing happened again, I then found a thread which suggested remove, clean, and replace the memory modules, this I also did, still no joy, once it is booted in to life it seems to be ok for a while if on a flat suface such as a table rather than on my knees, it also seems to help if I use an external mouse, so as not to actually touch the laptop to often, this works for anything from 2 minutes to an hour or so but it still freezes eventually... this is a very frustrating problem and I am willing to try any suggestions to resolve this problem any help would be much appreceated.

Please Help Ivan