I had the same problem after loading the latest patch and I resolved the problem.
The ps3 would turn on and just sit at the wavy line.
I initially installed the latest patch directly on the ps3 through it's
internet connection. To fix it I had to download it and copy it to a sd
memory card (camera memory) and insert that into the sd memory slot on
Follow this procedure for proper setup of the update file.
Here is what i did to fix it.
-hold down the power button for 2 separate beeps. It will turn on then off. Take finger off button.
-after it powers off (light red) press the power again and hold until
you hear a single beep (or 2) then a double beep. After the double beep
stop pressing the button. (it took me a couple of tries to get to this
-This will bring you to a menu
-Select install update option
-insert the sd memory card or usb memory card/stick.
-the ps3 will find the update and reinstall.
-let the install finish and let it reboot on it's own.
This worked for me. Hope it works for you.