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Re: Inspiron 1100 Memory Upgrade Questions

My Dell Inspiron 1100 had one 512 MB card, and I wanted to buy a second such card to upgrade it to the maximum memory capacity of 1 GB. I installed a 512 MB card from crucial.com that matched all the specs for this machine. When I put it in the DIMM B slot with the old 512 MB card in DIMM A, I could boot to the BIOS config screen but the screen didn't display right. Thinking there might be something wrong with the new card, I decided to try only one card at a time. So I removed the old (working) card and moved the new card to DIMM A. In this configuration, it wouldn't boot. Instead it flashed two of the three lights next to the power button for 5 seconds and then powered itself down.

Thinking the card was defective, I returned it for a replacement, but the next card behaved the same. I went through 4 more cards. All of them failed the same way. One of them was even manufactured by Dell! Yet my old card worked fine, so I knew the problem was related to the new memory card and not a problem elsewhere in the laptop.

I Googled for others who had encountered the problem but nobody had an explanation for why the problem occurs. I have now figured out why some memory cards fail in the Dell Inspiron 1100 and others work.

Here's the reason some memory cards won't work in Dell's Inspiron 1100 and others will. Count how many chips are on the card. Divide the card's memory capacity by the number of chips. If the result is more than 32 MB, it won't work! The designers assumed that no chip on a memory card would ever have more than 32 MB.

By releasing a piece of hardware with this limitation, they created a situation where a memory card can match all the specs (DDR PC2100, 200 pin SODIMM, CL=2.5, Unbuffered, Non-ECC) and still be incompatible because with this hardware design, maximum memory per chip on the card is an unpublicized spec. that will prevent the machine from working if the chips exceed the 32 MB limit!

If you have a 512 MB card with 8 chips on it, it will never work. The only ones that do work are the ones with 16 chips.

The 1100 hardware design also has numerous other problems which are described at http://www.lieffcabraser.com/dell-inspiron-3.htm.