I have a 4gb ram 1333mhz ddr3 attached to my pc. It was working fine before i remove it bcos i have to change my motherboard. I have it sold, and after the buyer tested it, they say it's not working anymore. I tried cleaning the ram with eraser and tested it with another pc but it's not working anymore. It has been only used for 2months so im wondering why it is not working anymore