I have the exact same problem with my 2005FPW. Has ANYONE (Dell included) discovered a fix for this? Have had my monitor beyond the warrenty period, and never a problem. A couple weeks ago, my screen would flicker, then a hissing noise, then turn off (actaully, it is just the back light as I too, like the earlier post, can very faintly see the winodws on my screen). Then, in the past week, there was no flickering, but the screen would hiss, then turn off after about 10 seconds. Now the backlight won't come on at all.
The only fix for this is to get it repaired. We do not offer this service. This company might be able to help you.
just bought one of these used and discovered it had the same problem...my tech son took it apart and discovered that one of the black power wires was pinched behind the screen and it has worn through. He re-soldered that part and that issue went away.
I suspect that there's a problem with the CCFL tubes used for the backlight. The hissing is likely high-voltage arcing. (The CCFLs run off of high voltage generated by the inverter circuitry on the power supply board.) One or more CCFL tubes may be defective or broken. The shut-down after so many seconds is the correct behavior of the inverter circuit. If/when it detects abnormal voltage or current to the CCFL tubes, it automatically shuts off as a safety precaution.
Replacement CCFL tubes are available from quite a few vendors on eBay and the Internet. Replacing the tubes is quite a complicated process, based on the two I have done, but it can be done if you are careful. There are how-to-videos around as well.