A friend gave me a non operating Dell Dimension E510 running WinXP. After much head scratching, I got it up and running, but after giving it to my son who lives in Colorado, he calls one day and advises me that all he gets now when he tries to start it is a blinking amber light. I replaced it with a new Hp and brought the Dell back to Indiana. After much research on this problem, I've discovered that this is not a rare occurrence with these particular models, but an epidemic. Dell claims the blinking light is either a malfunctioning power supply that's not supplying, or else a motherboard that has stopped mothering. I removed the mother board to see if there was something shorting it out but found nothing. Checking the power supply with a multimeter, I discovered with the 12v P2 connector disconnected, all the voltages were pretty well right on, but once I connected the P2 to the motherboard, the fans and the HD stopped spinning, and all the voltages dropped to nearly nonexistent. I'm wondering if the power supply is breaking down under load or if the motherboard has given up the ghost. What should I replace??? Or should I replace anything?? This is a hobby to me, but after refurbishing these older computers, I give them to people that really can't afford a computer. Any input will be much appreciated.... Jim said that!