Bad memory socket?

[tbwilson4]

I have a 600e 26458BU currently running 160 mb ram. Whenever I try to add additional memory to the forward open socket, I start getting system errors, lockups, and reboots. I have tried 4 different 128 mb memory units,all new & correct for this unit, and have also moved the good memory from the back slot to the forward slot with same results. Bad socket? Repairable, or would this require a whole new motherboard? Works fine with 160 mb! Thanks!

[rkawakami]

Welcome to thinkpads.com!

From your description, I think you've narrowed it down properly. The "forward" slot sounds like it has a problem. As a sanity check, try running a memory diagnostic program such as:

http://www.memtest.org/ (memtest86+)

with NO modules installed (i.e., just your 32MB on-board memory), then one 128MB module installed in the back slot and then the front slot. Allow at least one complete pass (two is better) of the memory diagnostic before declaring it "passing". My guess would be that for 32MB in a 400Mhz system will take about 9 minutes to complete one pass. 160MB should take about 40 minutes. Of course these times will be for passing modules; a failure will probably show up right away.

It may be possible to fix the memory socket if it's a matter of a broken solder joint but if it's anything beyond that, you are probably looking at a replacement motherboard. As an aside, you can put a low density (16 chip) 256MB module in the back slot for a total of 288MB.

[tbwilson4]

Thanks! I am pretty certain it's a socket issue as I have run memtest on the 32mb & on 3 separate 128 mb units in the good back socket. Can't run any type of test on questionable socket because as soon as I add any memory, makes strange buzzing noise during bootup, system reboots to memory post screen. So if I understand you correctly, I can use a 256mb module in the good socket to combine with the 32mb to get my 288? I thought each socket was limited to 128mb max. That would be a fix I can live with!

[rkawakami]

There is one problematic 600 (not an E) which seems to have an issue with some modules in the front slot:

http://forum.thinkpads.com/viewtopic.php?t=51580

I have a 600E (2645-4AU) with two 256MB low density (16 chip) modules running Windows 98. 288MB would probably be okay with W98 or 2000; I wouldn't recommend it for Windows XP.

[tbwilson4]

Glad I found this forum! I will try to pick up a single 256mb module and not even bother with the bad socket. Thanks for the assistance!