Miscellaneous laptop discussions : SOS SOS Laptop Gurus

SOS SOS Laptop Gurus

I recently bought an Inspiron 6400 with Intel Core 2 Duo T7200 processor, 120GB 5400RPM HDD, 1GB DDR2 533MHz. Despite the fact that the notebook works flawlessly to my entire satisfaction yet I noticed my fan humming all the way from boot to shutdown with the exception of the fan shutting down for 5-6 minutes during any 5 hour work session. This happens when I am just surfing the net or messenging. SO you can pretty well imagine wahts gonna happen if I start seriously working. Here is a list of what I tried uselessly to resolve the issue:

1. Checked the fan and vents for any clogging or obstruction
2. Placed the notebook on firm wooden desk with plenty of air flow.
3. The room's aircondition is always ON so the room is chilled.
4. Uninstalled more than 50% of the software.
5. Disabled ALL START UP PROGRAMS and stuff
6. Disabled more than 80% of the background services/apps running.
7. Altered the Power settings and made the processor limit to 35%.
8. Checked with AC Adapter and without plugging in.
9. Checked for any spyware,malaware, adware etc
10. Updated the BIOS to latest available version.
11. Fine tuned the BIOS and even set it on Default
12. Reinstalled / restored the entire system to factory default.
13. Boot the system in Safe Mode also.
14. Disabled/Shutdown one core out of two but it further worsened the situation.

This is all I could do but the fan wont give up on spinning continuously. It just stops for a few minutes and then kicks in. Although its not audible too much and may not be an issue to some people but it is annoying for me in a sound dampened room. Any other ideas i could try?

And by the way, i tried this on three other similarly configured Dell Inspiron 6400 laptops and the feature/prob remained. Is this due to more heat generated by Core 2 Duo T7200 processor as one of my friend pointed out?

A third party Dell notebook fan and temperature control utility shows that the temperatures are OK and Dell Diagnostics reveal that the fans and other hardware is OK too.