The major plan at this time, regardless of whether the T43 became a backup computer or not, was to give the T43 a little maintenance. I decided that I wanted to take it apart and clean out the fan/cooling unit, apply new thermal compound and give it a general check. I almost suspect that the laptop read my thoughts about this, because it suddenly decided to have the cooling fan die. At first the fan only made a barely audible humming noise, but it soon developed into a louder, grinding noise, and I didn't feel comfortable having the laptop running without me being around it. A seized fan can have bad consequences like overheating and even blow fuses on the motherboard. So, it seemed like I had to bite the bullet and get started with the project earlier than I had planned to.
After posting on the forum, I once again got in contact with Brad, which offered me a fan $15 cheaper than Lenovo sell them for, so we did a deal again. The fan is a part of a complete unit consisting of the heatsink, and the heat transfer pipes. I also purchased a small tube of Arctic Silver heat transfer compound, and I was ready to go.
IBM always made very good HMM (Hardware Maintenance Manuals) for their products, so I made sure to read trough this first. I also prepared a piece of cardboard with holes in, to keep track of the screws I had to take out, and their location. The first screws hold the keyboard, which can be slid back and lifted out after the screws are removed. The next part was to unscrew and take the palmrest/keyboard bezel off, and suddenly I had access to the internals.
The T43 with the keyboard, keyboard bezel and heatsink unit removed. The fan/heatsink unit can be seen on the right side of the machine. Also notice the cardboard used to keep track of the screws.
The heatsink unit is held by three screws, and the T43 Type 2668 uses a so called "long fan" that covers both the CPU and GPU chip. The heat transfer from the CPU is done by contact transfer, aided by thermal compound, while the GPU part uses a heat transfer pad between the GPU top plate and the heatsink. Unfortunately this pad gets very stuck to the GPU over time, and due to the potential loose GPU failure, the GPU is the last component you want to expose to any kind of stress/force. The GPU failure is not so likely to happen on the T43 as it is on the earlier T4x machines, but you still want to be very careful.
The ATI GPU with the heatsink removed. Notice the red epoxy dots around the edges of the GPU and the South and Northbridge chips. The epoxy, in addition to improved soldering techniques, made the T43s much less likely to experience the loose GPU failure than the previous T4x laptops.
So I ended up using dental floss to cut into a corner of the heat transfer pad and compound that filled the space between the GPU and the heatsink. In the end I had enough open room to put the tip of a screwdriver in between, and being very careful not to apply twisting or lifting forces to the GPU, I managed to lift the heatsink off. After unplugging the fan cable, the entire unit could be lifted out.
The new heatsink came with dots of thermal compound preapplied at the point where it makes contact with the CPU, but I removed that and applied the Arctic Silver. The pad for the GPU was there too. Then I put the unit back, and fastened the three screws. I also triple checked that I really reconnected the power cable for the fan. The last thing I wanted to do was to pull the laptop apart again just because I forgot that. One point to notice is that one of the screws holding the keyboard bezel needs to be put back after the keyboard is back in place. The HMM gives specific instructions on this, so it's highly recommended to read through this before you do this.
It's always exciting to do the first boot up after messing with the internals of a computer, but my repair seemed to have turned out just fine. The laptop booted up, and there were no noises from the fan anymore. I am even planning to download and install CPUID to monitor the temperatures, just to be in 100% control. I regret I didn't install CPUID earlier, so I could have been able to compare the temperatures now to what they were before I changed the fan and put new thermal compound on.
So, with a new fan, a new battery and a new hard drive, I hope the T43 will serve me well for more years to come. If it becomes a spare laptop, and is no longer used on a daily basis, my guess is that it will last for a very long time.
