Troubleshooting Charts: TX RF

9-27

 

 

 

TX RF—Page 3

3

 

 

 

 

 

 

 

 

 

 

 

 

Measure

 

 

 

RAWB+

 

 

 

at Q107-drain

 

 

 

 

 

 

Check

 

 

 

 

RAWB+

No

 

about

 

continuity to

 

 

7.2 Vdc?

 

 

J1-1 thru E101.

 

Yes

 

 

 

 

 

 

 

 

 

 

 

 

Measure

 

 

 

gate bias

 

 

 

at L108

 

 

 

 

 

 

 

 

 

 

 

 

 

V.gate

No

 

Check

about 2-3 ￿

 

continuity of

 

 

Vdc?

 

 

nodes to TP111

 

Yes

 

 

 

 

 

 

 

 

 

 

 

 

PA has low gain.

 

 

 

Replace Q107.

 

 

 

4

Measure TEMP voltage at R130

TEMP

No

Repair temperature

sensor circuit

voltage < 1.0 Vdc

 

 

(U103, R129,

at 25∞C?

 

 

 

 

R130).

 

 

 

 

 

Yes

 

 

 

 

 

 

 

 

 

 

 

 

Measure RFIN

 

 

 

DC voltage at

 

 

 

TP101

 

 

 

 

 

 

 

Check RF detector

 

 

 

 

 

 

 

 

TP101

No

(D101, C118, R107,

R103, R109) and

< 0.5 Vdc?

 

 

 

 

 

 

coupler (U101, R104,

 

 

 

 

 

Yes

 

 

R110, R118, R119).

 

 

 

Repair defects.

 

 

 

 

 

PCIC is bad.

 

 

 

Replace U104

 

 

 

MAEPF-27476-O

6881094C12-A

November 11, 2004

Page 131
Image 131
Motorola SSETM 5000 service manual Temp