Panasonic KX-TD500 System Reference Manual page 1449

3.28 DTMF receiver failure (SLC/ESLC/MSLC/HLC/DHLC/OPX card)
Error Code
Possible cause of
the malfunction
Countermeasures
Note
9 rxx
xx= 01 to 40 : Slot number
r= 1 to 4 : DTMF Receiver number
1) Defective DTMF receiver.
2) Defective path for the DTMF receiver from the faulty port.
Set working receiver to OUS
Is the DTMF dialing (0~9,
from the extension SLT in the faulty
card acceptable ?
OK
Set faulty receiver to OUS, another
receiver to INS, perform port test for
the "port" in the faulty card and the
"port 1" in the smallest physical
numbered COT card
NG
Perform the same test on
other COT card
NG
Replace the TSW card, and perform
the same test as above
NG
Replace the faulty card, and perform
the same test as above
NG
Replace the shelf
End
None
, #)
15-E-31
NG
Replace the faulty card
OK
OK
OK
OK