How long have you had the set for, and when did the problem occur?
Was it after a storm or power outage?
Does the standby/timer light blink continuously, or in a pattern (such as 5 blinks,pause, 5 blinks, pause, etc.)?
Please disconnect the set from AC power, then press and hold the power button on the TV itself (not the remote), for 10 seconds. After another minute, plug the setback in and press power once. Do you still have the same problem?
The 4 blink code on your set indicates a protective shutdown due to a short seen on one of the outputs of the power supply. This is typically caused by faulty SDR boards on the Plasma panel of the TV. Unfortunately this requires voltage testing to determine if the problem is the boards, or the power supply itself having a fault. The average cost for this type of repair is going to be between $250-$400 parts and labor depending on which board has the fault. You can use the link below to locate a Tech in your area if you'd like: