Tx rf—page 3 – Motorola SSETM 5000 User Manual

Page 131

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6881094C12-A

November 11, 2004

Troubleshooting Charts: TX RF

9-27

TX RF—Page 3

No

Yes

Measure TEMP
voltage at R130

No

Yes

Measure RFIN 

DC voltage at

TP101

TEMP

voltage < 1.0 Vdc 

at 25∞C?

 PCIC is bad. 

Replace U104

TP101

< 0.5 Vdc?

Check RF detector

(D101, C118, R107, 

R103, R109) and

coupler (U101, R104, 

R110, R118, R119). 

Repair defects.

Repair temperature

sensor circuit
(U103, R129,

R130).

4

MAEPF-27476-O

RAWB+

about

7.2 Vdc?

Measure

RAWB+

at Q107-drain

No

No

Yes

Yes

Check

continuity of 

nodes to TP111

V.gate

about 2-3 

Vdc?

Check

continuity to

J1-1 thru E101.

PA has low gain. 

Replace Q107.

Measure

gate bias

at L108

3

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