Problem with failing memory slot
Information about the failing memory slot on the T30 model.
One of the two memory expansion slots in the T30s fails after some time. This is also encountered in some T2x series Thinkpads, and eventually this problem can occur in both memory slots if it is not repaired early enough. Hot weather seems to induce the failure.
IBM will replace motherboards of machines under warranty.
Quite often the problem occurs first in the secondary memory slot. The root cause of the failing memory slot in T20/T30 series laptops is in fractured solder joints between the RAM memory module socket legs and the motherboard. The solder joint micro-fractures arise after a few years' use as the heavy and unsupported memory module sockets are located under the motherboard. Exposing the laptop frequently to even minor shocks or vibration (e.g. placing the laptop daily onto a table or port replicator) will cause slow fatigue to the solder joints as the memory modules are basically hanging unsupported on the bottom side of the motherboard, and all vibration will cause them to move microscopically small amounts up and down. Eventually the fatigue of the solder joints will be creating a crack on one or more joints, being visible using a stereo microscope.
Permanent fix: The best way to repair the broken solder joints in a permanent way is to re-solder all the memory module socket legs after removing all memory modules and the laptop battery. The repair can be performed either by a qualified electronics repair shop or a skilled electronics hobbyist using a very narrow-tipped soldering iron (e.g. Weller or Metcal), some liquid soldering flux needed for treating the solder joints before re-soldering them, a stereo microscope for accurate viewing of the work area, and of course a good skill in electronics soldering. Using this procedure it is often possible to save and permanently repair a Thinkpad T20/T30 series laptop without replacing the motherboard. After the solder joint repair it is a good practise to place a well-supporting soft padding (thick adhesive tape etc.) between the installed memory modules and the memory panel/door that covers the modules, preventing this problem from occurring again after a few years.
Temporary fix: The problem can often be corrected temporarily by applying pressure to the RAM memory modules, thus making a better contact in the fractured solder joints mentioned above. One way to do this is to cut a small strip of metal and fold it in half. Then tape it to the inside of the memory panel so that when the panel closes, it places pressure on the middle of the affected module. Close the door (may not shut all the way), and boot the system. The computer should regcognize all RAM again. If the primary slot fails, the computer will fail to POST, or lock up during boot. In this case it is absolutely necessary to make the permanent fix mentioned above.