My trusty old (5 years or so) Dimension has finally sat down on me. Fails to power up to the point where BIOS talks to display. Power light on front of cabinet is solid amber. Have tried swopping/reducing memory, removing all option cards, removing all disks, DVDs, &c. All voltages measure OK on P1, except for pin 14 (PS_ON), which reads zero. Pin 8 (POK) reads 5.1V, but of course, I've no idea what these would be were the darn thing working. At no time do any of the four LEDs at the rear show any signs of life. Anyone out there got any ideas? I'd hate to buy a PSU and then find it was the motherboard. Although I worked on computers (large systems - yes, I know, I'm a dinosaur!) before I retired, I'm no expert now; but my shakey hands are still capable of holding a voltmeter.