I've owned this Dell for about a year (second owner)  and in the last three weeks the cooling fan for cpu/heatsink has taken a drastic change in its operation. When the pc is started, it starts relatively normal but over the next 10 to 15 seconds it seems to ramp up to its maximum speed (6000 RPM). I did a lot of reading and this fan isn't your typical type of a cpu fan (current rating is 2.3 A).For the last two weeks the pc has been "parked" as I will not continue to use it until this problem is resolved.

As someone who has quite a bit of experience in pc (both software and hardware), I did a lot of reading and searching. Following many advices I have exhausted my options and hope someone will be able to help me. In reading many threads relating to this specific problem I performed the following actions in order to fix my pc;

1.Cleaned the pc heatsink of any dust or air blokage (I make a point of monthly cleaning all my pc's) and therefore I did not expect this to be a cause for this problem;

2.There are no bulging or leaky capacitors on the motherboard;

3.There are no orange lights (diagnostic faults) on the back of the pc. All are green coloured;

4.Removed the cpu/heatsink assembly and cleaned the surface of both with isopropyl alcohol. Applied a fresh coat of thermal grease to cpu surface and reassembled the two;

5.In reading one of the other threads with the same problem I attempted to reverse the cpu fan . Rather than exhausting the air from inside the pc case, it's blowing over the heatsink but I still found the fan too noisy when it's running at full speed;

 6. I installed software to monitor both the cpu temperature and cpu fan speed and the only parameter outside its norm was the fan speed (< 5750 RPM);

In one of the threads, a community member ("shesagordie") suggested to replace the original fan with Zalman CNPS 7700-Cu . I have purchased the fan but after some analysis can not see how this fan can be inserted in place of the original. The Zalman mounting bracket is a standard  socket 775 where the original heatsink bracket is a proprietary Dell version. Drilling through a multi-layered board can only invite more trouble as it is too easy to damage one of the copper traces. The link that was provide on the Zalman installation leads to a 403 error>>

I am in Canada and there is no access to this server. If anyone would be kind to post the installation guide to another location, I would be very grateful.

Incidentally, my family owns three other Dell pc's (6400 Inspiron, Dimension 8300 and Dimension e510) and this is my first time I am seeking technical help.

 Thank you for your help.