a20m RAM problem

[C-Man]

Here are my specs:

500MHz Celeron

40GB Hard Drive

Big Smokestacks



I've been having issues with the original 128 MB RAM, mostly issues in running out of RAM! :smileyvery-happy:

I did my research and found that I can bump it up to 512MB of PC100 RAM. I got myself a couple of 256MB PC100 sticks and popped them in there.

...

...

Nothing. Doesn't show the POST screen, or any screen at all. Okay...

So I switched the two chips around, made sure they were seated good. And nothing. I figured maybe I had to reset the CMOS, so I pulled one of the new chips and put in one of the old 64MB chips.



It POSTed alright, and only showed the old 64MB chip. Like the 256 chip wasn't even there.



I can't for the life of me figure out what I'm doing wrong. It's highly unlikely that I got two bad RAM sticks, and they're both definitely the right kind for this laptop. Is there anything at all I'm overlooking? Please help!

[rkawakami]

Welcome to thinkpads.com!

The "right kind" of 256MB memory for the A20m would be ones which have 16 individual memory chips on the module; 8 per side. These are generally known as "low density" modules. It sounds like the ones you have are "high density" - those have a total of 8 chips (4 per side). The IBM-certified modules which work in those old systems will have a part number of 33L3069 or 33L3070.

[C-Man]

Oh...
Apparently I do have the high-density ones. *sigh
Glad I only paid thirty bucks for these.
Thanks for your help.

[ajkula66]

Also, Celeron-based A2x machines will not be able to use more than 256 MB and only in 2x128 MB format AFAIK.

[C-Man]

Uhh...
Now I've got a new problem.
Don't know how, but I think I might have broken one of the original sticks.
I tried to put the old RAM back in, and now only 64MB will show up. I switched them around, and got a 1-1-1-1 beep code. I never should have messed with it.

[wackyD]

May be too late, but did you install both sticks at the same time?

I have had success installing one, getting it recognized and then installing the second after shutting down.

Good luck.

Daniel

[C-Man]

I got a couple of 33L3069 sticks as suggested, and they work 100% perfect. I guess I did fudge one of the old sticks, though I can't imagine how. Anyway, now I'm waiting for an SL53S P3 processor, which should arrive today. This one I have checked and triple-checked for compatibility, and have found more than one person who performed this exact same upgrade, so it should work for me. Even without speedstep, it should be a good upgrade, and the chip only cost $20.

EDIT: It works! And it's bloody fast, too. It says it's running at 700 MHz, but it behaves more like it's running at the full 1GHz. I cut a ton off the XP boot time, and everything pops right up now.

[Dave7417]

Also, Celeron-based A2x machines will not be able to use more than 256 MB and only in 2x128 MB format AFAIK.

The A20M Celeron (I have a 550) supports 512 max ram, in any configuration. I am currently running 384 meg using 128 & 256. Runs like a charm. (Different ram manufacturers too.) Over the years I have run different combinations of 32, 64, 128, and finally 256 meg sodimms as I upgraded. (Ram was very expensive ten years ago.) I am half tempted to get another 256 to upgrade to the 512 max, but I have no reason too. (LoL)

Long time lurker, first time poster. I finally registered so I could respond to this post. I bought my A20M (2628-1VU) new in 1999. It runs like a clock. Absolutely trouble free. My other notebooks are a Fujitsu P4 1.7, and a Sony Centrino 1.86, but every now and again to crank up my old favourite, the IBM.