Try unplugging the PS3 for 30 minutes from the AC power.
Also try lowering your video resolution on the PS3 to 480P initially.
If these both fail, try hot plugging the PS3 into the TV while both are turned on AND/OR changing the TV's input away from the PS3/HDMI input and then come back to it. Both of these last two force the TV to initialize a handshake with the PS3. Good luck, I hope something works for you.