35
KX-TG4753B/KX-TG470B/KX-TGA405B
10.1.3.2. Handset
Cross Reference:
Power Supply Circuit/Reset Circuit
(P.20)
10.1.4. Check Record
10.1.4.1. Base Unit
Not record Incoming Message
Cross Reference:
Signal Route
(P.25)
Telephone Line Interface
(P.14)
Parallel Connection Detect Circuit/Auto Disconnect
Circuit
(P.15)
Note:
Flash Memory is IC601.
BBIC is IC501.
Check
Power Supply Circuit/Reset Circuit
.
Check X1, C8, C9.
Is the voltage of TP 3.0 V about 3.0 V?
Is the voltage of TP-VBAT 2.3 V more?
Check the battery and around BATT+ and
BATT- are not shorted.
Is the battery inserted to BATT+ and BATT-?
Does BBIC (IC1: 86) oscillate at 13.824 MHz?
YES
YES
YES
NO
NO
NO
Is the voltage of TP VDDC about 1.2 V?
NO
YES
Check BBIC (IC1).
YES
Check Bell signal.
OK
Check
Telephone Line Interface
[Bell].
Does the unit catch line?
YES
Check
Telephone Line Interface
[OFF HOOK].
Check Line In: Pin 16 of BBIC.
Check ICM Recording in
Signal Route.
NO
OK
Check
Auto Disconnect Circuit.
OK
Check
Parallel Connection Detection
Circuit.
OK
Check BBIC and Flash Memory.
NO
NO