Thinkpads Forum

I have a 2645-31U and just installed 2 PC66 128MB chips. These laptops are supposed to max out at 280. When both chips are in it only sees 224MB. When only one chip is in the back bank it sees all 160MB. When only one chip is in the front bank it only sees 96MB. These numbers include the 32MB built-in. Anyone know why this is and how to fix it?

Do you have or have you tried the latest BIOS update? Doing that is my recommendation.

MadeInJapan wrote:Do you have or have you tried the latest BIOS update? Doing that is my recommendation.

Indeed I do.

I guess you have tried swapping the the new chips in the front bank, without any chips in the back bank? It the result is 96Mb in both cases, I would suspect your memory slot is defective. Try to make sure all the contacts are clean.

I could be wrong here, but that is what I think.

EDIT: I did see this just now on another thread. Read the posts near the bottom of the thread by Dan MacLeod and sickofit. Maybe your memory is not really PC66, but PC100.

http://forum.thinkpads.com/viewtopic.ph ... ight=224mb

It is a know fact that some old TP600 recognize only half of the memory
capacity put into the second DIMM slot due to system board design. It seems
like your TP600 is this case, meaning that 128+128/2+32=224MB.

So if that's the case then there is no known solution eh? Drat.

As far as I know, there is no solution.
You have to abandon the half of one DIMM.

This probably won't work, but... can you remove the 32MB module that's "built in"? If yes, I'd try that, then put in both 128MB modules. Maybe (maybe) it will recognize 256 (total) with the 32MB taken out...???

Why not try disableing the onboard ram rather then risking damageing your board with a soldering iron. I I can remember correctly get into the bios click on config, hit control+d look for an 81 on the bios 128 CMOS page, change the 81 to an 80, and then see if it picks up on the other ram.
You can also try buying a can of air and blowing into the defective slot.
The ram may also be defective, If you have the cash purchase a used
600E motherboard off ebay, that picks up 512 with the latest bios update, and low density 16 chip ram sticks.
Hope that helps

Yes, of course, good point! If it's soldered on there, don't even think of trying to remove it.

Nope, disabling ram just reduced my ram by 32mb. Guess buying a 603e motherboard is the best option. What's the average price I outta be able to get one with some savy bidding and patience? Also, is there a manual out there for opening the case to do a swap? Didn't think I could add a 603e board, that there was some sorta issue with the screen size or something.

SnakeEyes wrote:Nope, disabling ram just reduced my ram by 32mb. Guess buying a 603e motherboard is the best option. What's the average price I outta be able to get one with some savy bidding and patience? Also, is there a manual out there for opening the case to do a swap? Didn't think I could add a 603e board, that there was some sorta issue with the screen size or something.

Can someone give me a little extra help here?

SnakeEyes wrote:

SnakeEyes wrote:Nope, disabling ram just reduced my ram by 32mb. Guess buying a 603e motherboard is the best option. What's the average price I outta be able to get one with some savy bidding and patience? Also, is there a manual out there for opening the case to do a swap? Didn't think I could add a 603e board, that there was some sorta issue with the screen size or something.

Can someone give me a little extra help here?

You can get them for $40.00 to $65.00 bucks on ebay.
This seems to be a common problem with the 600.

Replace the 600 board W/ a 600E.