When a computer can turn on with power, but nothing appears on the screen and you don’t hear any ominous noises, then a memory failure can be occurring. Sticks of memory are located in the memory slots inside the computer. Depending upon the computer, they may have to be inserted in pairs. When there is a memory failure, it can occur in two different ways. The actual stick can be defective, which is the more common way. Or, the slot that the memory goes into can be defective, which is very rare. Either problem can occur when the computer is a victim of a power problem, a brown-out or a surge. Hence, if you absolutely must ensure that your computer has “clean” (level) power, then a battery UPS (uninterruptible power supply) should be purchased to provide at least some time to shut the equipment down gracefully in case of a blackout, and to provide missing power in case of a brown-out.