I’ve been on kick upgrading the memory in my HP printers (as a friend of mine once said, “If you’ve got an open slot, fill it.”), and the latest and most difficult by far has been the HP Color Laserjet 2840. I started at crucial.com, where I buy the majority of my memory, but for once they did not sell any for this printer. After searching some, I found some no name websites selling the memory, but the memory always referred to Laserjet 4100. I went to HP’s site, tracked down a part number, did more searching and found the memory again. This time, the site I was on referred to an HP part number and a Kingston part number. I went to Kingston.com and searched and found the part, which again said it was for the Laserjet 4100 series. For some reason they had a link to buy.com for the same memory only cheaper, so I ended up buying it at buy.com.
The memory package says LJ4100/128 (128MB stick), but the buy.om slip said module for HP Laserjet 4100 1320 2800 MFP. Bingo, 2800 series, that’s me. Now I felt comfortable installing the memory. It went in easily and came up to the max 224MB of memory.
If you own an laser printer that allows memory upgrades, I recommend it. It will speed up printing large jobs and the memory is fairly inexpensive.