Operating instructions

800/900 Band Troubleshooting Charts 9-5
No
Yes
Yes
Yes
No
No
No
Yes
No
No
Yes Yes
No No
Yes
Yes
No
Yes
900MHz VCO
No
Yes
Yes
No
No
No
Yes
No
Yes
No
Yes
No
Yes
No Yes
Yes
START
4.5VDC at collector
of Q203?
1.7-1.9VDC at base
of Q203?
Is C028 at 1.0V -
9.5VDC?
5VDC at collector of
Q205?
Inspect L200, L201, L202, D200,
D201, C204, C206, C207, C208,
C209, C210, C211 & C216
A
A
800MHz VCO?
1.0 - 1.2VDC at
emitter of Q203?
Inspect L204,
R202 and Q200
Inspect L203,
R200, & R201
Inspect L205,
R203, & Q200
2.3VDC at base of
Q205?
1.5VDC at emitter of
Q205?
2.7VDC at pin 6 of
U200?
Inspect R213 &
R215
Inspect R216,
C244 & Q205
Inspect R233 &
Q202
Inspect L216 &
Q202
TX c arrier?
0.75V at pin 2 of
D202?
Inspect R217, R218, R220,
R221, R222, C217, C238, C239,
C240, C245, C246, C247, C248,
C251, L213, L217 & L218
Inspect R212, R217, R218, R219, R220,
R221, R222, D202, C217, C238, C239,
C240, C245, C246, C247, C248, C249,
C250, L213, L217 & L218
Inspect R224 &
Q206
Signal ~6dBm (for RX mode) at
pin 3 or ~3dBm (for TXmode) at
pin 1 of U201?
Inspect C251 for RX path
& C249 for TX path
2.5VDC pin 6 (for
Rx) or pin 4 (for Tx)
of U201?
Inspect pin C5 of U001 for RX
and include Q001& R019 for TX
4.5VDC at collector
of Q204?
1.7-1.9VDC at base
of Q204?
Is C028 at 1.0V -
9.5VDC?
Inspect L206, L207, L208, D204,
D205, C220, C222, C223, C224,
C225, C226 & C231
1.0 - 1.2VDC at
emitter of Q204?
Inspect
L210,
Inspect
L209,
Inspect L211,
R211, C254 &
B
B
Troubleshooting Flow Chart for VCO