Toshiba M400 Fan Hack
Well it has been awhile but there is no one out there who has solved the fan noise issue. Neither speedfan, notebook hardware control and some other utilities out there are supporting fan control in the M400.
Well, I took matters into my own hands. Do this at your own risk. It most definitely will void any warranty but it was worth a shot.
I have been doing some research into CPU temperatures and I have found some interesting info over at the Intel web site. It seems that the temperature rating is much higher for mobile processors, 100c vs. 61c, ready to boil water anyone? Here are the specs for the Core Duo 2GHz T2500.
I don't really have time to outline all the disassembly and reassembly steps, but you are basically ripping everything out. If you need to replace the fan, you will also have to remove the motherboard.
The first step is to remove the Battery, Hard Disks, Media Bay, and any SD cards. You then remove all of the screws, note the size and the number of the screw. This will help you add the screws back when you need to reassemble. There is a plastic piece right over the keyboard, below the monitor that you can pry off with your fingernails. This will allow you to remove the keyboard and get at the insides.
You will need to remove all of the metal doors and plastic covers. You don't need to remove the RAM. Next you need to remove all of the leads to the keyboard, monitor, modem, and WIFI. Make sure that you have a really small torx screw driver to remove the WIFI antenna. Otherwise you will break the antenna leads. Luckily they are available on EBay for cheap.
Finally you will need to remove the screws holding the screen in place, there are three. After that you can remove the whole top assembly and you should have something that looks like this.
As you can see I have removed the fan, carefully not disconnecting from the motherboard. If you do you will have to remove the motherboard. I took a gamble an decided that the red lead is one of the power leads and spliced it and attached it to a switch which I placed in one of the holes available for the extra slice battery, which I had at one time but returned. The next picture is the switch installed. If you look carefully, I trimmed the switch so that it won't catch anything. There is still enough to grab onto with a fingernail to turn on and off.
So there you have it. If you can remember where all the wires and screws go, hopefully you won't have anything left over, you will no have a near silent tablet PC.
The only thing that you still need is a program, RightMark Clock Utility. This utility will allow you to monitor the CPU clock and temperature. It will also enable you to enable thermal throttling so you won't over heat.
I definitely recommend to underclock you machine 1GHz when you turn off your fan. Although the CPU has thermal limiters the other components on the motherboard or system may not like 100c.
Happy Hacking..