My old Sony Vaio PCG-GRX3P (hell expensive when I bought it) has for the last few months experienced an intermittently faulty LCD backlight. A couple of weeks ago I decided to get it repaired so sent it in to my local Sony repairer. Nearly fell off my chair when I got the quote for 770 dollars (which I had to pay 99 dollars for) for an entire new LCD panel. At that price it is not feasible to repair - the laptop is about 4 years old and other components will be likely going to the big electronic graveyard in the sky soon. For under 1000 dollars you can now get a pretty good brand new laptop.
So. I decided to do some research on possible problems with the screen. I was fairly sure the screen was OK because only the backlight goes on and off. Research indicated it was most likely a) the backlight b) the inverter c) a connection between. Knowing the backlight does work sometimes, I was sure the backlight was OK. The backlight is essentially a tiny fluoro light, so I reckon if it was dead we'd get nothing - no intermittent blink. That narrowed the field to inverter or connection. My money was on the inverter.
At this point I did what all good nerds do and dismantled the screen into pieces so I could see what I was dealing with. To my surprise when I messed about with the inverter and shorted a couple of bits out the screen came to life (BIG WARNING: DO NOT DO THIS UNLESS YOU HAVE A VAGUE CLUE WHAT YOU ARE DOING. YOU WILL DIE. Inverters have an output to the CCFL (backlight) of between 700-1000 volts. This is enough to kill you until you're dead). So I was now 90% sure the inverter was the issue.
Jumped on to ebay and searched for the part number on the inverter. Presto. A company in Chicago USA was selling one for 25 USD. Ordered. Done. Wait about a week for delivery.
It arrived today and I popped it into the LCD panel. Worked perfectly. Total time to install and reassemble, about 10 minutes. Total cost 38USD. Plus of course the 99 dollars it cost to get a quote for the replacement of a part that was not broken. Think I might write them a nasty letter.