It is a multi-step (and quite expensive) process, but worked for me:
- Get a heat pump installed (nowhere near the PC, not even using the same power circuit)
- Arrive home and start computer, discover no response from screen
- No power indication
- No backlight
- No video
- Restart computer, thinking screen may be stuck in sleep mode
- No sign of life from screen
- Check power and video connection to screen
- No sign of life from screen
- Plug screen into different power source (in case bad outlet on UPS), then directly into another wall plug with no UPS or power strip
- No sign of life from screen
- Change video cable
- No sign of life from screen
- Give up, wonder if power coming back on after heat pump install knocked out the screen. It was sometimes a bit flaky restarting from sleep mode and about 5 years old. As there were no power LEDs or backlight decide it is probably dead.
- Go shopping,
- Purchase new screen
- Plug in new screen and connect video
- Start computer, no sign of video from NEW screen although power light is on
- Check video cable, plugs again, no sign of life from NEW screen
- Restart computer, no sign of life from NEW screen
- Shut down computer, open case, remove video card and put it back in the same slot
- Start computer and enjoy crisp clean video on new screen
- Curious, reconnect old screen to enjoy similarly glorious results on the old screen
- Find a spare video cable and set up old screen beside new one
- Enjoy, while feeling slightly mystified, the new dual monitor set-up in the warmth of the new heat pump.