Motorola MTP700 - Page 101

TRANSCEIVER 400 MHz MTP700 Portable Radio / Detailed Service Manual 4.1 - 67
DC Distribution (V3_2.775V/PWM1_1.8V) Test
Use this test on a unit with the following symptoms: no V3_2.775V, no PWM1_1.8V.
No
Yes
Yes
No
Is the volta
ge OK?
Is the volta
ge OK?
No
Yes
Refer to the DC Distribution
(V3_2.775V) Test flowchart.
Check L200.
Check C224, C226, C243, C248
for 1.88Vdc (PWM1_1.8V).
Check C209, C258, C259 for
2.775Vdc (V3_2.775V_DIG).
Is the volta
ge OK?
Check C242, C201 for 3.3Vdc
(GCAP3_1).
Check E302 ferrite bead at
REDCAP2 (U301) for opens.
Check for chopped voltage at
junction L202 / D202.
Yes
No
Is the volta
ge OK?
Check D202 for polarity.
If OK, replace GCAP3 (U200).
Replace L202, D202 if
necessary.