Panasonic SA-PT480PH Service Manual page 61

Step 11 Remove 4 screws on Main P.C.B..
Step 12 Remove 6 screws.
Step 13 Release the tab of the right side of the Rear Panel in
the direction of arrow.
Step 14 Lift up to remove Main P.C.B. Shield Unit.
Step 15 Remove the Main P.C.B..
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