Check The Rf Part - Panasonic KX-TG4221N Service Manual

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
KX-TG4221N/KX-TG4222N/KX-TG4223N/KX-TG313SK/KX-TG4224N/KX-TG4225N/KX-TGA421N
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Registration of
handset to
Regular BU
Yes
(checked ones)
37
No
Handset is defective