My laptop has 256K memory

Question

My laptop has 256K memory installed. I purchased 512 RAM (max I can add is 1024) and installed it in my hp Pavilion zt1230 laptop. Per Kahlon.com instructions, I cleaned gold leads with eraser and popped it into place. I turned computer on and computer will not start up. It is dead until I pull memory out. This is the 2nd time and 2nd different memory chip in tried. I verified with Kahlon.com that this is correct chip. Even though I have lifetime warranty and they guarantee compatibility, Kahlon.com told me to sell chip on Ebay. Any suggestions why this is not working in my laptop? I have the latest BIOS.Helen