0. Unplug z computer completely and wait 5-10 min 1. Remove battery 2. remove all memory(RAM) 3. replace 1 memory card in unused slot 4. Reboot computer (it rebooted) 5. repeat steps 3 & 4 with other memory card(s). If any do not work - you have a faulty memory card 6. If all memory cards work, replace battery, and put memory cards back in original slots 7. Reboot Hop it helps;-)