Motorola Gm Series Detailed 6864115b62 B Manual

Troubleshooting Flow Chart for 25W Transmitter (Sheet 1 of 3) 3-5
2.2Troubleshooting Flow Chart for 25W Transmitter (Sheet 3 of 3)
Check Final PA Stage
NO 0V
1-4VBias 2 DC 
Voltage at 
TP4406?
YESRF Voltage 
at TP4401 
>100mV?
YESRF Voltage 
U4401 Pin 6 
>3V?
Supply
Replace Q4441
Check FGU (U4301)
NOCheck Components 
between 
TP4401  &C4417
NO YESASFIC  
U0221 Pin 6 
1-4V DC?
Check Bias Tuning 
before replacing ASFIC 
U0221
Check Components 
between ASFIC and 
Q4441 before 
replacing Q4441
YESRF Voltage...

3-6TROUBLESHOOTING CHARTS
3.0 Troubleshooting Flow Chart for UHF 40W Transmitter 
No
Is Q4441 OK ?
Ye s
Is drive from VCO
        >+4dBm? NoIs voltage drop across
     R4497 >4.5V ?No
Check Q4431 gate(open)
and drain resistances
            (11kohm)NoCheck Q4421 gate(open)
and drain resistances
             (11kohm)No
        Check
PCIC_MOSBIAS_1
No
No
Change
Q4473 
              START
        No power
  
  Is Vctrl
there? Is Q4473
   OK?
Check voltage
on Pin 5 U4501
Check R4422-5
and go back to top...

Troubleshooting Flow Chart for Synthesizer3-7
4.0 Troubleshooting Flow Chart for Synthesizer
5V
 at pin 6 of 
D4201
Is
information
from
 mP U0101
correct
?
Is
U4201 Pin 47
at = 13VDC
?
Is
U4301 Pin 19
4.5 VDC in TX?  
(at VCO section)
?
Start
Visual 
check of the 
Board
OK?Correct
Problem
Check 5V
Regulator
U4211
+5V
at U4201
Pin’s
13 & 30
?
Is
16.8MHz
Signal at U4201 
Pin 19
?
Check
Y4261 / Y4262 and 
associated Parts
Are
signals
at Pin’s 14 &15 
of U4201
?
Check 
R4201Check C4381
Is
U4201
Pin 2  >4.5...

3-8TROUBLESHOOTING CHARTS
5.0 Troubleshooting Flow Chart for VCO
Are Q4332
Base at 0.7V 
Collector at 4.5V 
Emitter at 110mV
Are Q4301
Base at 2.4V 
Collector at 4.5V 
Emitter at 1.7VAre U4301 Pins
13 at 4.4V
15 at 1.1V
10 at 4.5V
16 at 1.9V
Low or no RF Signal
at TP4003
Visual check
of board
OK?
35mV DC at
U4301 Pin 19
NO
YES
Replace Q4301
at base of Q4332
NO
NO
NO
NO YES
YES
YESYESLow or no RF Signal
at input to PA
4.8V DC at
U4301 Pin 19
Is RF available 
at C4402
YES
YESYES YES NO
NO
NO
NO
NO
Audio...

Chapter 4
UHF PCB/SCHEMATICS/PARTS LISTS
1.0 Allocation of Schematics and Circuit Boards
1.1 Controller Circuits
The UHF circuits are contained on the printed circuit board (PCB) which also contains the Controller 
circuits. This Chapter shows the schematics for the UHF circuits only, refer to the Controller section 
for details of the related Controller circuits . The PCB component layouts and the Parts Lists in this 
Chapter show both the Controller and UHF circuit components. The UHF schematics and...

4-2UHF PCB/Schematics/parts lists
Table 4-3   UHF 1-25W Diagrams and Parts Lists
PCB : 8485670z03  Main Board Top Side
8485670z03  Main Board Bottom Side Page 4-23 
Page 4-24
SCHEMATICS
Power Amplifier 1 - 25W 
FRACN
Voltage Controlled Oscillator
Receiver Front End
IF
Page 4-25 
Page 4-26
Page 4-27
Page 4-28
Page 4-29
Parts List 8485670z03 Page 4-30
Controller version is T9
Table 4-4    UHF 25-40W Diagrams and Parts Lists
PCB : 848612 7z01  Main  Boa rd  To p  Sid e
84 8612 7z01  Main  B oa rd Bo ttom S...

LB Range1, 25-60W PCB 8486206B06 / Schematics4-52.0 LB Range1, 25-60W PCB 8486206B06 / Schematics
C0101
C0102
C0104
C0105
C0106
C0107
C0121C0131C0132
C0211
C0212
C0221
C0222
C0223C0225
C0226
C0227
C0228 C0231
C0232
C0233
C0234
C0235 C0236C0237
C0241
C0242 C0243
C0244
C0245C0246 C0251
C0252
C0253 C0254C0255
C0256
C0261
C0262
C0275
C0290 C0291
C0292C0293C0331
C0401 C0441
C0442
C0443
C0445
C0446
C0447
C0448
C0449C0451
C0452
C0453
C0455
C0456
C0457
C0458
C0459
C0460
C0461
C0462
C0463
C0464
C0466
C0467
C0468...

4-6LB Range1, 25-60W PCB 8486206B06 / Schematics
C0103 C0111 C0112C0122
C0123
C0141
C0151 C0201
C0202
C0203
C0204
C0205
C0224C0265 C0266C0267
C0271
C0272
C0273
C0274
C0276
C0277
C0301C0302
C0303
C0304
C0305
C0324C0325
C0341
C0342
C0343
C0344
C0351
C0352
C0353 C0354
C0402C0403
C0406
C0407
C0408
C0409
C0410
C0411 C0421
C0422 C0423C0426
C0427
C0428
C0429
C0430 C0431
C0485
C0491 C0492
C0497C0499C0541
C0542C0554
C0558C0559
C0560
C0575
C0576 C0591
C0592
C0593
C0611C0621
C0622
C0641
C0644C0645
C0661 C0662...

LB Range1, 25-60W PCB 8486206B06 / Schematics4-7
1.8V-2.2V
1.8-2.2V
1.75Vpp 1.8V-2.2V
12Vpp
J1401 L1423
430pF124.327nH
130pF
C1481
C1422
FN0:NOTPLACEDC1449
4.7uH .01uF
16
RFIN6
RFOUT1
7
RFOUT2 1
VCNTRL
14
VD12
VG1
3
VG2L1402
4
GND1
5
GND2
12
GND3
13
GND4
8
NC1
9
NC2
10
NC3
15
NC4
U140130C65
17
EP
11
G2
C1413
.01uFL1424
56nH
FN0:NP 1uF C1425
10 R1421
.01uF C140510uFC1458
75pF C148656pF
180 R14541uFC1452
C1471
C1469
.01uF C1468.01uF
0C1433
1uF
27Vpp
78Vpp2Vdc
143Vpp189Vpp186Vpp
27Vpp
R14820.1uF
C1402C1529...

4-8LB Range1, 25-60W PCB 8486206B06 / Schematics
6.00V (44W) 3.00V (72W)
2.90V (44W) 2.46V (72W)
1.86V (44W)
6.34V (72W) 2.51V (72W)
1.90V (44W) 0.825V
9V3
Q1504 Q1502
R1508
1% 43.2
D1503 D1502
R1545
4.7K
Q1506C1532
10uF TP1505
680CSX TEMPSENSE_PA_1
R1537R1501
1000pFC1531 1.5K39.2
1% R1535
.01uFC1530
R1515
R1524 1K
680 100K R1510
1.5KR1541R1511
100K
1000pFC1505
100KR1512Q1503
82K R1532 R1502
470
U1502 2
31 8
4CLK_PA_1DATA
7 8
4FECNTL_1_PA_1 9T1_PA_1
U1502 6
59V3_PA_1
R1509
100K
C1512 R1522
10K
1uF C1509...