Panasonic KX-T336 System Reference Manual page 1461

3.07 Expansion shelf power down ( AC )
Error Code
Possible cause of
the malfunction
Countermeasures
Note
051n
n = 1 : Expansion Shelf 1
2 : Expansion Shelf 2
1) Power failure
2) Power Supply Unit malfunction of the Expansion Shelf n (n=1 or 2), or trouble
with the Power Supply System (Backboard, CPU card) of the Shelf
Did the above item 1) occur at the
recorded time of the Error Log ?
No
Is there a new error message in the
Error Log, when the RESET button
is pressed ?
Yes
Does the trouble occur frequently ?
No change in
condition
No change in
condition
*It is recommended to have a current copy of the program on disk or tape to
facilitate accurate and rapid recovery.
14-E-10
No
Yes
Replace the Power Supply Unit
Replace the CPU card*
Replace the Shelf
End
Yes
No
OK
OK