Thinkpads Forum

600x 2645-9FU
PIII 650Mhz
2x128mb RAM (+64mb Interal RAM)
WXP SP3

I purchased & installed (2) 256mb PC100 NP chips, but now on boot-up the system freezes at the RAM Counter which details the correct amount in the system(576mb)OK. IBM & ThinkPad logos are present.

F1 does not work. F12 does work, but will not allow me to access Setup from the F12.

I have removed all components, unplugged CMOS for 30mins. and reinstalled all items to no avail.

I also replaced the RAM with the (2) 128mb chips and it runs fine. I have also run it at 64mb internal, slow but runs.

What do I need to do in order to recognize the full RAM and run properly?

Thank You,
James

Welcome to thinkpads.com!

Since the 128MB modules work, then your problem must be with the 256MB sticks. The 600X requires use of "low density" 256MB modules. As such, you should see 16 individual memory chips (8 per side) on them. If they only have 8 total components, then those are "high density" versions and will not work inside the 600X. Assuming for the moment that they are low density, then I would download a copy of memtest86+ and run each module individually. You can get the diagnostic program from here:

http://www.memtest.org/#downiso

Would the High Density sticks be the reason the RAM counter is showing 589248kb?

64 internal + (2) 256 = 576000 - (not 589248)

Do you know of any companys that sell the proper RAM?

Thanks,
James

No, 589248KB would be the proper display for 64MB + 256MB + 256MB. It's what my 600X shows as well. I'm not sure if the 600X would get as far as displaying the RAM count if you have installed high density modules, so that's why I asked. If you can confirm that your two 256MB modules are low density (16 chips on board), then it could be possible that there's a defect in one (or both) of the modules so that's why I suggested running a memory diagnostic.

There's many online sellers of these modules. What you can look for is the IBM FRU of 33L3069 or 33L3070. Those part numbers denotes the proper memory sticks for a 600X, although you will probably pay more because of that part number. A Micron MT16LSDF3264 module is equivalent. Crucial.com is a division of Micron and they can supply the proper module. Do a Google search on those FRU numbers and you'll turn up other sellers. Just be sure that there's 16 memory components on the module and that the seller guarantees that they will work in your 600X and that they will either refund your money or swap modules if you get a defective one. eBay also has sellers which offer low density modules if you can wade through the muck to find a gem.