Panasonic KX-TG7731S Service Manual page 41

10.1.6. Check the RF part
10.1.6.1. Finding out the Defective part
1. Prepare Regular HS(*1) and Regular BU(*2).
2. a. Re-register regular HS (Normal mode) to base unit (to be checked).
If this operation fails in some ways, the base unit is defective.
b. Re-register handset (to be checked) to regular BU (Normal mode).
If this operation fails in some ways, the handset is defective.
After All the Checkings or Repairing
1. Re-register the checked handset to the checked base unit, and Regular HS to Regular BU.
Base unit is defective
Note:
(*1) HS: Handset
(*2) BU: Base Unit
No
Registration of
Regular HS to
base unit
Yes
(other checkings)
Registration of Regular HS to Regular BU
Registration of handset to base unit
START
Registration of
handset to
Regular BU
Yes
(checked ones)
41
KX-TG7731S/KX-TG7732S/KX-TG7733S/KX-TGA470S
No
Handset is defective