Recognizing memory in T43 - 2686DFU

[jellinek]

Hello all,

I've had a Thinkpad T43, model #2686-DFU for about a year and a half now. I've had no major problems with the 2686 until I tried to add a 1GB RAM chip to the additional memory slot on the bottom of the unit, to make 1.5GB total (I left the original 512MB chip in the main memory slot under the keyboard).

I powered up the computer and the new memory was recognized immediately in the BIOS and Windows XP, SP2. Everything worked fine for a few months, until I noticed the computer running slow. I checked, and the 1GB chip was not being recognized anymore.

Both pieces of memory are working fine--whichever one I put in the main memory slot under the keyboard is recognized without a problem, so I figure the problem must be with the additional memory slot itself.

The strange thing, which makes me question whether the additional memory slot is completely dead, is that I can get the computer to recognize whichever card is in the additional slot if I: 1) power down the computer and remove the memory from the additional slot; 2) boot up the computer, log in, and then shut down; 3) remove the battery and discharge the computer by holding down the power button; 4) replace the additional memory card; 5) and power back on.

Every time I follow this procedure, both the main memory slot and the additional memory slot recognize the memory, for a full 1.5GB, for that session--but once I shutdown and power it back on, the memory in the additional slot won't be recognized again without removing it and going through the above procedure.

For the time being, I've put the 1GB chip in the main slot so I can at least use that regularly. If anyone has suggestions about how to fix this, and whether it's a known problem, etc., I would really appreciate hearing from you!

Also, as a note, the computer is unfortunately no longer under warranty, and I can't afford any expensive repairs with Lenovo.

Many thanks in advance for your help!

Regards,
Robert Jellinek

jellinek*at*fas.harvard.edu

[richk]

This is tough. The only things I can suggest are first to make sure you have the latest BIOS and Embedded Controller files, even I cannot find a mention of a similar problem in the fixes. Then I would clean the memory socket with spray cleaner for electronics.

[Johan]

- comment redrawn!