Motorola MTP700 - Page 201

TRANSCEIVER 800 MHz MTP700 Portable Radio / Detailed Service Manual 4.2 - 79
Open Loop Power Test (Cont.)
Measure the RF power at pin 24 of LNODCT
(U803) and input of I/Q splitter U801.
Is the level >0dBm?
No
Yes
B
Perform Escort
section tests.
Measure the RF power at input and output of I/Q splitter (U801)
Calculate the difference between I/Q splitter input and output.
Is the difference
>3.5dB?
No
Yes
Check I/Q splitter U801, C827,
C828.
Replace faulty parts.
Perform the Open Loop Power
test again.
Measure the ASW level on pin 28 of LNODCT
U803 during Tx slot by using scope. Does the
ASW level go low (about 0Vdc) during Tx slot?
No
Replace LNODCT U803.
Perform the Open Loop
Power test again.
Verify by using scope that:
1. There is 2.4MHz clock (1.8, 0.3Vdc) on pins 11, 12 of U803 during Tx slot.
2. SLT and SLTB go low on pins 9, 10 of U803.
Yes
Do the two
conditions exist?
No
Yes
Perform "WPIC Test"
Perform the Open Loop
Power test again.
Verify by using scope that there is an input data on pins 58-
61 of the LNODCT U803. (AC voltage 300-400mV peak)
Was any data
detected?
Perform LNODCT U803.
Perform the Open Loop
Power test again.
Yes
No