d. Test procedure 53. When measuring continuity on the J-3513/U J5 pin
A to the RT chassis ground, the circuit is good (Test procedure 52).
Disconnect the CX-13061/U from the KY-57 RAD jack.
Reconnect the handset to J-3513/U J5 and rekey the handset.
Disconnecting CX-13061/U from the KY-57 RAD jack with the RT power
ON, provides power to the J-3513/U.
K2 energizes, causing K2B
contact to change. This takes the KY-57, CX-13061/U, and CX-13062/U
out of the keying circuit, dividing the bad circuit (Figure 84).
If there is no keying, the J-3513/U or MT-1029 is bad. If there
is keying, the J-3513/U, KY-57, CX-13061, or CX-13062/U is bad.
RT keying circuit, no RT keying.