Check Link - Panasonic KX-TG4753B Service Manual

10.1.7. Check Link

10.1.7.1. Base Unit
Does Base Unit make link with normal working
Handset?
NO
Is the voltage of VBAT about 3.0 V?
YES
Is the voltage of VDDC about 1.2 V?
YES
Is the voltage of +3.0V about 3.0 V?
YES
Does the RF clock (CLK) oscillate at 13.824 MHz in
Base Unit Test Mode?
YES
Check the RF part
Cross Reference:
Power Supply Circuit/Reset Circuit (P.12)
Check the RF part (P.42)
Note:
*1 How to adjust +3.0V:
Execute the command "VDA"
Refer to Things to Do after Replacing IC or X'tal (P.64) for Base Unit.
*2 How to adjust the frequency of X501:
To see the frequency, execute the command "SFR", then check the TP_CKM (IC501-57pin).
To adjust frequency, send command "SFR
YES
Base Unit is OK. Check Handset.
NO
Check around Power Supply Circuit.
NO
NO
Adjust +3.0V voltage to 3.0 V.
OK
Check around X501 and RF module and adjust
NO
clock frequency.
"until the frequency counter becomes13.824 MHZ±55HZ.
39
KX-TG4753B/KX-TG470B/KX-TGA405B
*1
*2