Laptop dropped, fan shuts off soon after startup

Alan77

Estimable
Dec 6, 2014
2
0
4,510
A little while ago my laptop was dropped and once I turned it on I got an error message about the fan. Now the fan will always turn on when I power up the laptop but will turn off within a few seconds. The laptop itself does not appear to shutdown due to overheating though, but if I do dare to log in and check the cpu temp, it's usually around 95C, at which point I shut it down again. At first I thought the fan was broken as I had dropped my laptop another time a few months ago, after which it would occasionally make some grinding noises, so I replaced the fan but that appears to have had no effect. I have also noticed that the fan does occasionally stay on if I first enter BIOS and then boot up into windows, but the temperature is still abnormally high, around 70 to 85C.

Which brings me to the second problem, which is that I can't seem to enter BIOS properly. I will simply get a blank screen for however long I hold in F2 after start-up and as soon as I let go the system will boot into windows. If I disconnect the HDD however, then I am able to enter BIOS normally.

I have tried resetting the BIOS settings to default, even removing the BIOS battery and letting it sit for a few minutes before replacing it, no difference. I read that it might be a power issue so I tried disconnecting the battery and letting it run directly from the power cord, but again, no difference. Is the motherboard simply done for and needs replacing? Any help is appreciated, thanks.

Toshiba satellite S50D-A-00G, running windows 8.0
 

BrandonYoung

Estimable
Oct 13, 2014
43
0
4,610
Dropping a laptop could do a multitude of things. It could bend the chassis in such a way that cooling is affected, sandwich fan blades preventing them from moving, knock the heatsink off the cpu, or leaving enough of a gap between the cpu and heatsink as to negate any cooling what so ever. It could break HDDs (which perhaps is why disconnecting the drive allows the bios to load).

As it sounds like your laptop is having some issues, perhaps you would not be opposed to opening it up, and un-mounting the heatsink (don't forget to remove the dust from the fan and the fins on the heatsink while you're at it). making sure it can properly mount to the cpu, and isn't cracked and leaking heatpipe goop anywhere. Make sure the chassis didn't bend and is now applying pressure to components that don't like pressure (fans...). Perhaps ensure that the fan is able to spin by gently rotating it with a finger.

Concerning the BIOS problem, are any "fast boot" options enabled that you're aware of? Instead of holding F2, have you tried pressing it really fast, over and over? Do you have another HDD you could try to verify that the drive is not at fault somehow?

Good luck.
 

Alan77

Estimable
Dec 6, 2014
2
0
4,510


Thanks for your reply.
I actually had to remount the heatsink when I replaced the fan, as they were both taped together, and the heatsink looked to be in fine condition, no visible cracks or heatpipe goop, and there was still good contact between the cpu and heatsink. I could not find any bend or anything in the chassis and the fan is able to spin well.

There is a fast boot option but it is disabled. Pressing F2 repeatedly and quickly has the same effect. Unfortunately I do not have another HDD readily available to test, but the fan still does not stay on consistently even with the HDD disconnected, so I do not think that is the main cause.