Thinkpads Forum

I bought an X61 a couple of days ago. It has a major issue. Sometimes it will just shut off by itself for no apparent reason, and other times it works perfectly fine. If it shuts down, it is always recently after booting it up, and always when it has just been on. Also, and I don't know if it is related, but I can only run one stick of RAM at a time. It doesn't matter which slot is used, both work, just not at the same time.

The RAM is fine. I have three sticks of DDR2 and they all test out well. I also just updated the BIOS to the most recent 2.22 from Lenovo. I am running Windows 8.1 on it, but the problem happens regardless of OS. The computer is not overheating. I took it apart and everything was clean. I replaced the thermal paste on the CPU and removed the thermal pad from the northbridge. I bent the heatsink to fill the gap, and I added thermal paste there too. The fan spins and seems normal.

I have had problems with a couple of X61s, which are close enough to an X61, it might be useful.

1. One X61s had freezes (not shutdowns). Memtest86 gave the appearance of bad RAM. However, swapping different sticks into the slots lead to the conclusion that it wasn't the RAM. It was discovered that the machine worked with one stick. Since the memory controller is in between the CPU and the RAM, this pointed to the memory controller. This is just like your situation. Solution: swap motherboard.

2. Replacement motherboard also freezes, but so occasionally, it's OK for a travel machine.

3. Yet another X61s shut down while running on the Ultrabase. The only thing of note is that it had been running several hours, and got very hot. There doesn't appear to be anything wrong with the machine or the fan, which blows hot air just fine. It just gets very hot on the Ultrabase, which IMHO is a design defect. Since this happened with the LV "s" version of the X61, I am surprised there have not been more thermal complaints.