So here is my situation, I've a Dell Studio 1558 laptop running on Corei3 Processor and about few months ago it stopped working, on powering on there would be no display although I could hear the heatsink fan running.
About few weeks ago I opened the laptop cleaned the heatsink fan and applied fresh thermal paste and after this it started to work again but the problem was the temperature of the processor (core 0, core 1) would remain above 60C even in idle state and recently the heatsink's fan wouldn't start and as a result the laptop wouldn't start due to over-heating.
To fix this I bought a brand new heatsink from eBay and installed it and below is the result:-
1) After installing the new heatsink, I turned on the laptop and visually tried to verify if the fan was working but the fan wasn't working even though this is a brand new heatsink.
2) To troubleshoot the heatsink fan issue, I removed the laptop's battery and cmos battery and pressed the power button for few seconds then installed the batteries and powered it on again and after this the heatsink fan was working.
3) I checked SpeedFan to see the temp and in idle state the temperature was around 45C-50C so the heatsink was working but after few minutes when I opened a browser the display went blank and I had to turn it off via long pressing the power button.
4) Now when I power on the laptop the display is blank and I get this continuous beeps, the heatsink fan is not working either which is obviously causing the processor to over-heat and probably the reason for the continuous beeps.
5) When I was using the old Heatsink and facing over-heating issues I bought a Deepcool cooling pad with 2 fans and it's after I started using this cooling pad that the old heatsink fan stopped working, I'm just mentioning this in case if these 2 additional fans effect the laptop's power consumption and has some effect on the heatsink fan.
I've wasted about a month troubleshooting this laptop, I have assembled and disassembled the laptop at least 20 times by now, so really desperate to get this laptop working again, so any helpful suggestions would be greatly appreciated.
UPDATED:- The solution to the heatsink fan problem is repeatedly pressing the F2 button on start up. This is weird but it's working every time. I was trying to get to the bios and that's when I noticed that pressing the F2 for some reason starts the heatsink fan. I've checked it couple of times and it worked every time.