Motorola MTP700 - Page 198

4.2 - 76 MTP700 Portable Radio / Detailed Service Manual TRANSCEIVER 800 MHz
Closed Loop Power Test
This test should be carried out only after the successful completion of the previous tests.
Tune the radio on PATS.
Is the radio close
loop output power
<28dBm or 31dBm?
Yes
No
OK
Check the elements: coupler U806, R913,
R914, R915, C845, C846, L809. Replace if
faulty and repeat the close loop test.
Does the close loop
power problem still
exist?
Yes
No
OK
Measure the LO power on pin 24 MVCO of
the LNODCT U803 (800-400m Vp-p (single
ended) swing into a 50 ohm load.
Does the close loop
power problem still
exist?
No
Yes
Replace LNODCT, perform Open Loop
Power test and Close Loop Power test.
Check R852. Replace if faulty, repeat Close
Loop Power test. If the problem still exists
replace LNODCT U803 and repeat Open
Loop Power test and Close Loop Power test.