Motorola Astro Digital Mobile Radio Xtl5000 Detailled 6881096c74 B Manual

							6881096C74-BMay 25, 2005
Troubleshooting Charts: Flowcharts5-61
5.6.47 RF Power Amplifier (RFPA)—No or Low TX Power Output (700–800 MHz)—
Part 4 of 5
Specific Notes:
1. Remove C6501 and solder the center conductor of a small 50-ohm, coaxial cable to 
VN_B6500. Solder ground to the gold shield track adjacent to VN_B6500. Attach an RF 
milliwatt meter, key the transmitter, and measure TX_INJ power. Then, remove the coaxial 
cable and replace C6501. Remove the solder added to shield track.
2. Remove R0977 in the power control section, and measure the resistance between VCNTRL 
(VN_B6503) and ground. Replace R0977.
3. If U6500, VD1, is incorrect, inspect the bias feed circuitry (L6501 and C6504) and interstage 
match components (L6502, C6506, and C6503). If U6500, RFOUT, is incorrect, inspect the 
bias feed circuitry (L6500 and C6500).
4. Remove L6501 and measure the resistance between VD1 (VN_B6501) and ground. Replace 
L6501. Remove L6500 and measure the resistance between RFOUT (VN_B6504) and 
ground. Replace L6500.
5. Inspect C6502, C6509-11, and R6521-5.
6. If the Q6520 gate bias is incorrect, inspect the bias feed circuitry (R6520 and C6520). If the 
bias feed circuitry is functional, then go to the Power Control—No or low VGBIAS flowchart. If 
the Q6520 drain bias is incorrect, inspect the bias feed circuitry (L6521, C6521-2, R6526-7, 
and L6521-5).
7. Remove R6520 and measure the resistance between Q6520 gate and ground. Replace 
R6520.
8. Remove L6521 and measure the resistance between Q6520 drain and ground. Replace 
L6521.
9. Inspect C6541-2, C6544-5, C6547-8, C6565-6, R6550-7, and R6559.
10. If the Q6540 gate bias is incorrect, inspect the bias feed circuitry (R6540 and C6540). If the 
gate bias feed circuitry is functional, then go to the Power Control—No or low VGBIAS 
flowchart. If the Q6541gate bias is incorrect, inspect the bias feed circuitry (R6543 and 
C6558). If the bias feed circuitry is functional, then go to the Power Control—No or low 
VGBIAS flowchart. If the Q6540-1 common drain bias is incorrect, inspect the bias feed 
circuitry (L6542-3, C6559-60, R6544-5, and L6521-5).
11. Remove R6540 and measure the resistance between Q6540 gate and ground. Replace 
R6540. Remove R6543 and measure the resistance between Q6541 gate and ground.  
Replace R6541.
12. Remove L6542 and measure the resistance between Q6540-1 drain and ground. Replace 
L6542.
13. Inspect R6560 and C6549-57.
14. If the antenna switch bias voltages are incorrect, inspect R6547-8, L6700, and L6702-3, as 
well as perform diode checks on D6701-2.
15. Inspect the remaining antenna switch parts (C6700-5).
16. Inspect L6720-2 and C6720-1.
17. Inspect D6730, R6730-2, R6735-6, L6730, and C6730-1. 
						

							May 25, 20056881096C74-B
5-62Troubleshooting Charts: Flowcharts
5.6.48 RF Power Amplifier (RFPA)—No or Low TX Power Output (700–800 MHz)—
Part 5 of 5
Table 5-7.  RFPA DC Voltages
DescriptionLocationVo l ta g e  ( V d c )
A+ = 13.6 Vdc
U5501, VD1 VN_B6503 9.0–9.3
U5501, RFOUT VN_B6504 9.0–9.3
Q6520 Gate Bias VN_B6520 2.0–2.2
Q6520 Drain Bias L6521/R6526
Node13.0–13.6
Q6540 Gate Bias VN_B6540 3.5–3.7
Q6541 Gate Bias VN_B6541 3.5–3.7
Q6540/Q6541
Drain BiasL6542/R6544
Node13.0–13.6
Antenna Switch Bias
Voltage 1VN_B6563 ~5.3
Antenna Switch Bias
Voltage 2VN_T6701 ~1.6
Antenna Switch Bias
Voltage 3D6701/D6702
Node~0.8 
						

							6881096C74-BMay 25, 2005
Troubleshooting Charts: Flowcharts5-63
5.6.49 RFPA Power Control—No K9.1V (700–800 MHz)
Figure 5-49.  RFPA Power Control—No K9.1V (700–800 MHz)
Read General
Notes before
proceeding. Read
specific notes as
indicated
START
Is 9.3V present at
Q0952, pin 5?YesIs Q0952, pin 4 
 < 0.5V when mic
button is depressed?Repair/replace
Q0952 Yes
No
Is K9.1V_EN > 2.0V
when mic button is
depressed?No
Repair/replace
Q0951
Is A+ present at U0951,
pin 4?
No
Yes
See GPIO in
CONTROLLER
section
Repair/replace
U0951
Yes
Connect battery
cable to supply
13.6VNo
MAEPF-27926-O 
						

							May 25, 20056881096C74-B
5-64Troubleshooting Charts: Flowcharts
5.6.50 RFPA Power Control—No VGBIAS (700–800 MHz)
Figure 5-50.  RFPA Power Control—No VGBIAS (700–800 MHz)
Read General
Notes before
proceeding. Read
specific notes as
indicated
START
NoYes
Repair/replace
U0960
No
No/low Q6540
VGBIAS1?
No/low Q6541
VGBIAS2?
Remove U0960.
TP0937 voltage
 2.6-2.8 V? Yes
Remove U0960.
TP0939 voltage
 2.6-2.8 V? Yes
Remove U0960.
TP0941 voltage
 2.0-2.2 V? No
Repair/replace
U0959.  If problem
still not fixed, see
IC communication
in CONTROLLER
section.
Yes
Yes
No
No
MAEPF-27928-O 
						

							6881096C74-BMay 25, 2005
Troubleshooting Charts: Flowcharts5-65
5.6.51 RFPA Power Control—No or Low TX RFPA_CNTRL (700–800 MHz)—Part 1 of 2
For each flowchart step in which reference is made to a note, be sure to refer to that specific note 
(located on page 66 of this flowchart) for guidance in performing the actual troubleshooting 
procedure.
Figure 5-51.  RFPA Power Control—No or Low TX RFPA_CNTRL (700–800 MHz)—Part 1 of 2
Read General
Notes before
proceeding, Read
specific notes as
indicated
START
Remove Q0954.
 Proper power
restored?
(Note 1)
Remove D0950.
 Proper power
restored?
(Note 2)Yes
No
U0956-3, pin 10
~ 1.5V?No
Yes
Repair/replace
defective parts or
see
Controller
GPIO section
Repair/replace
defective parts
No
VCC3 present at
U0963, pin 5?
(Note 3)VCC5 present at
U0963, pin 1?NoSee
Controller
VCC5 section
Yes
Remove R0974.
 VCC3 present at
U0963, pin 5?
(Note 4)YesRepair/replace
defective parts
Repair/replace
U0963No No
Repair/replace
defective parts
YesYes
A
TP0955 voltage
~ 1.5V?
Repair/replace
defective parts Yes
A
Remove D0951.
 Proper power
restored?
(Note 5)Repair/replace
defective parts
Yes
No
VFORWARD buffer
functioning properly?
(Note 6)U0959 functionally
properly?
(Note 7)
No
Repair/replace
defective partsYes
Repair/replace
defective parts or
see
Controller
GPIO section
No
MAEPF-27927-O
Go to
Controller
GPIO Section
NoYes 
						

							May 25, 20056881096C74-B
5-66Troubleshooting Charts: Flowcharts
5.6.52 RFPA Power Control—No or Low TX RFPA_CNTRL (700–800 MHz)—Part 2 of 2
Specific Notes:
1. Remove Q0954. If proper power is restored, repair/replace Q0954. If the problem still 
persists, check for proper operation of U0958-1, and replace U0958 if not functioning 
properly. If U0958-1 operation is correct, refer the controller section in the theory of operation 
chapter.
2. Remove D0950. If proper power is restored, inspect R0942-5, R0991, and U0956-4. Replace 
D0958.
3. Inspect R0974-5.
4. Remove R0974. Measure U0963, pin 5 voltage. Replace R0974.
5. Inspect the current limit and temperature cutback circuitry (refer to the power control section 
in the theory of operation chapter).
6. Adjust the Power Detector Calibration via the Tuner software (see the tuner Help text) and 
monitor the output power while the transmitter is keyed. If the circuit is functioning properly, 
output power will decrease if the softpot is increased, and output power will increase if the 
softpot is decreased. If the circuitry is not functioning properly, then inspect U0952, U0956-2, 
R0971-3. If the problem persists, refer to the controller section in the theory of operation 
chapter.
7. Retune the Power Detector Calibration if any circuitry is repaired/replaced.
8. Adjust the power via CPS (see the Help text) and monitor output power. If the softpot is 
decreased, power will increase; if the softpot is increased, power will decrease. If the circuitry 
is not functioning properly, replace U0959 and retune the power via CPS (see the Help text 
for complete procedures). If the problem persists, refer to the controller section in the theory 
of operation chapter. 
						

							Chapter 6 Troubleshooting Waveforms
6.1 Introduction
This chapter contains images of waveforms that might be useful in verifying operation of certain parts 
of the circuitry. These waveforms are for reference only; the actual data depicted will vary depending 
upon the operating conditions.
Table 6-1.  List of Troubleshooting Waveforms
WaveformPage
Power-On Reset Timing6-2
Power-On to Soft Turn-On Timing6-2
Power-Down Reset6-3
16.8 MHz Clock Waveform6-3
32 kHz Clock Waveform6-4
DSP SSI Port RX Mode6-4
DSP SSI Port TX Mode CSQ6-5
SPI Bus Waveform6-5
SB9600 Waveform6-6
SB9600 BUS+ and BUS- Waveforms6-6
SB9600 BUS+ and RESET Waveforms6-7
SB9600 BUSY and BUS- Waveforms6-7
RS-232 RX Waveforms6-8
RS-232 TX Waveforms6-8
RS-232 RX/TX Waveforms6-9
USB Waveforms6-9
Serial Audio Port Waveforms6-10
Secure Interface Waveforms6-10
8 kHz Frame Sync Waveform6-11
RX Audio Waveforms6-11
TX Audio Waveforms6-12
TX and RX 1 kHz Audio Path Sinewave and Chart6-12 
						

							May 25, 20056881096C74-B
6-2Troubleshooting Waveforms: XTL 5000 Waveforms
6.2 XTL 5000 Waveforms
6.2.1 Power-On Reset Timing
6.2.2 Power-On to Soft Turn-On Timing
MAEPF-27853-OCh3Ch1M5.00ms
Ch16.0 VCh2
U0507 Pin 5
LV_DETECT (POR) 13.8V
Ch1
SWB+
5.00V
2.00V2.00V Ch2
MAEPF-27854-O
Ch3Ch1M  200ms
Ch16.0 VCh2
U0507 Pin 5
LV_DETECT (POR)
Ch3
TP050013.8V
Ch1
SWB+
5.00V
2.00V2.00V Ch2 
						

							6881096C74-BMay 25, 2005
Troubleshooting Waveforms: XTL 5000 Waveforms 6-3
6.2.3 Power-Down Reset
6.2.4 16.8 MHz Clock Waveform
MAEPF-27855-O
Ch3Ch1M 10.0ms
Ch16.0 VCh2
U0507 Pin 5
LV_DETECT
Ch3
TP0500
SOFT_TURN_OFFCh1
SWB+ 13.8V
5.00V
2.00V2.00V Ch2
Power-Down Reset
Trace 1 — SWB+
Trace 2 — LV_DETECT — U0507 Pin 5
Trace 3 — SOFT_TURN_OFF — TP0500
MAEPF-27856-O
Ch1M  25.0ns
Ch110mV 500mV
C1 Pk-to-Pk
1.70V
C1 Period
59.333ns
Trace 1 — U0903 Pin 3 — 16.8 MHz Clock 
						

							May 25, 20056881096C74-B
6-4Troubleshooting Waveforms: XTL 5000 Waveforms
6.2.5 32 kHz Clock Waveform
6.2.6 DSP SSI Port RX Mode
MAEPF-27857-OTrace 1 — R428 — 32 kHz Clock
2
Ch3 Ch1T
1
3
M 20.0us  Ch1           2.2 VCh1 Freq
18kHz
5.00V
5.00V5.00V Ch2
MAEPF-27858-O
DSP SSI Port RX Mode CSQ
Trace 1 — ABACUS_SSI_FSYNC
Trace 2 — ABACUS_SSI_RXD
Trace 3 — ABACUS_SSI_CLK (1.2 MHz)