+ 0 Votes Possible you have a hardware failure, wizard57m-cnet January 24, 2013 at 12:52pm PST or perhaps loose memory chip, or some other component. If you are not comfortable in disassembling your computer, it may be advisable to seek technical help. Otherwise, you'll need to open the case, all cables, component cards, etc. to make sure each is making good connection. Clean the system from any dust, make sure the air vents are not blocked. Reassemble and try to boot. Did this start occurring suddenly, or have there been other symptoms showing up lately?