Fujitsu P7010 Notebook Overheating, Fan Noise, and BSOD: Part 2 (Repair)
by Clifford Vincent Arrow
July 2008
Making My Own Thermal Interface Material
(1) From a scrap piece of aluminum bar I purchased from Home Depot for a previous project,
(2) I cut 2 little squares to size to just be slightly thinner than than the total gap between the heatsink plate and the processor dies. (See sidebar.)
(3) I then "butter" both sides of my aluminum squares using Dow Corning 340 Heat Sink Compound, a non-conductive, non-running heatsink compound that is quite capable of filling in gaps for effective heat transfer.
Repair of Thermal Interface Material
Before reassembly, now is an excellent time to relubricate the fan sleeve bearing, especially if it is making noise. (See sidebar.)
(1) Northbridge and processor dies, my custom aluminum heat transfer squares, and OEM heatsink plate are cleaned with alcohol and Q-tip swabs. Remember not to touch any of the heat transfer surfaces with your oily fingers after you have finished cleaning!
(2) Apply Dow Corning 340 on the dies and carefully place aluminum heat transfer squares on them sandwiching the Dow Corning 340 heatsink compound between the dies and the aluminum squares.
(3) Apply Dow Corning 340 to the top of the aluminum squares. Then place heatsink plate over aluminum squares. I gently pressed down, then lifted to make sure everything aligned.
(4) Secure securing heatsink plate to motherboard with screws.
Repair Results
The repair turns out to be a success. Before reassembling the p7010 notebook, I again observe the temperature of my reference point near the northbridge die after 10 minutes after power-up. (Ambient temperature is about 80F in both temperature observations.)
The temperature at now (2) 115F vs (1) 134F before the thermal interface material repair.
More importantly, where the laptop would experience a (3) blue screen of death in under 2 hours, it is now reliable at the 14 hour mark and still going strong.
But Wait! There's More!
(1) I discovered this nifty utility called Notebook Hardware Control that allows you to lower your notebook's systems voltages. The advantages: cooler operating temperatures (i.e., crotch burner light), longer battery life, longer system life, and quieter (less fan noise). The disadvantages: Requires a little trial and error and some testing to ensure notebook is runs reliably at the lower voltage.
(2) However, with the Fujitsu notebooks, many users have found that they can significantly lower their default voltages yet keep their notebooks stable.
(3) In deciding my lowered voltages, keeping in mind that a rough "safe" voltage reduction is ~0.2V, I chose ~0.1V to be conservative.. The result: even cooler temperatures! How about another 8F degree drop at my reference board near the northbridge chip!
And the Temperatures Keep Dropping!
(2) Fixing the air gap between the processor and northbridge dies with custom aluminum squares and Dow Corning 340 heat sink compound reduced the temperature to 115F with reliable 14-hour-plus operation.
(3) Reducing the system voltage by about 0.75V with the Notebook Hardware Control reduced the temperature to 107F.
Final Notes
In conclusion, you may not have the exact same problem with the exact same model laptop I have, but I suspect the general problem of overheating on PC and laptop motherboards accounts for a large number of failures out in the field. The smallness of a laptop makes cooling via an AC duct viable as a quick test to see if an instability (BSOD) problem is a hardware (i.e., overheating) or software (e.g., Windows drivers) problem. Also, it is evident of the importance of proper chipset cooling (e.g., good thermal conduction between chipset dies and heatsink material via the appropriate thermal interface material.Article TOC
