Multiple squiggly lines fill the LCD screen, after

Sounds to me like your inverter has gone bad. Typically it's situated just below your LCD. To get to it you will have to take out the screws around the LCD bezel. It's a long, skinny circuit board that the LCD plugs into. You can usually find a replacement on Ebay. Just be sure that you're ordering the correct part, otherwise it may not fit or work properly. I've also had times when the entire LCD was going bad and the display was full of squiggly lines. It's hard to say which one is the cause. I would try replacing the inverter first. That part is usually much cheaper than the LCD is.