how do i fix a hp vf17 flat panel display backlight?you can recycle the display off then on and it stays on for 2 secs?

display still works but image is dark

Typically problems with LCD's not powering up or staying on are indicative of a faulty capacitors (or more likely a few bad caps). Fortunately capacitors are quite easy and cheap to replace. You can typically replace a bad cap with just a soldering iron and some pliers. If you know where to shop you can also get caps really cheap, I would look on Digikey or Mouser.
Before you go ordering caps though check to see if it is the capacitors. You can do this by disassembling the LCD; take a good look at the main boards in the LCD. Bad capacitors typically look bulged or are leaking, do a Google image search for bad capacitors if you need more clarification.
Another excellent resource is:
http://www.badcaps.net/
They have tons of great info, try searching there page for your model of LCD if that doesn't return any results try searching using the model number of the board that has bad caps, many manufactures will use the same boards in different LCD's.
Hope this helps and good luck.