This is the ONLY copy of this manual I could find for a realistic price. Even Panasonic could not provide me with one.
The PDF is a very good copy and it helped me diagnose and find the fault with the unit I have.
Text excerpt from page 185 (click to view)
TH-42PA20U-P
9.2.
CD mode
Select the CD mode by Up/Down button on the remote control at the front page of CAT mode then press the Mute button on the remote control more than 5 sec.
Micom software version (IC9354), this version can be upgrade by 1. replace of new version IC 2. Loading the new version software from loader tool, TZSC07036. Memory data change
To exit the CD mode, press the RECALL button on the remote control.
9.3.
SD mode
Select the SD mode by Up/Down button on the remote control at the front page of CAT mode then press the Action button on the remote control.
To exit the SD mode, press the RECALL button on the remote control.