Panasonic KX-T336 System Reference Manual page 533

2.03 Background Diagnostic Error List
Basic
shelf AC power down
Legend:
MJ-Major Alarm
X : applied
MN-Minor Alarm
Blank : not applied
PFT-Power Failure Transfer
LED-Refer to Section 14-E-2.00 "Troubleshooting via the LED indicators."
14-D-5