I have an E6510 laptop that recently started giving me an Error M1001 - fan malfunction on start up. I get this message only 1 in 4 or 5 times of boot. I am always able to hit F1 and continue the boot. Recently, I replaced the HD with a new 1 TB drive. The laptop came with Windows Vista installed originally but I have replaced this with Windows 7. The laptop has an i7 Intel Core.

I have opened the chassis and cleaned the air vents and replaced fan with a brand new fan assembly. I also cleaned and reapplied heat sink thermal grease. The computer works fine but I still get the Error M1001 message sometimes during boot in the morning.

I would appreciate any help or advice about solving this issue.

Thanks.