Panasonic TC-P55VT60 Technical Troubleshooting Manual page 64

Troubleshooting 12 Blinks Failure
Blink List of boards likely to cause this symptom.
Code
No.1 No.2 No.3 No.4
12 Speaker/
A
Blinks Subwoofer
Start Here
Unplug the TV and remove connector A12 from the A board. Plug in the TV and turn it on
Is the TV still
No
Yes
shutting
down with 12
blinks?
Disconnect the speakers
one at a time to determine
which one is bad Replace the A
board
Slide