Motorola Astro XTL 1500 - Page 168

6815854H01-A June 15, 2005
Troubleshooting Charts: Troubleshooting Tables 5-7
Radio Dead, Display
Lights Up with FL
01/90
Regulators • Check for SW_B+ at Q0503,
U0500-4, U0950-4, U0951-4
• Check for 9.3 V at U0500-5,
U0950-5, U0951-5.
• Check for 5 V at U0503-5, 3 V
at U0962-3, 2.85 V at U0501-1,
1.85 V at U0507-1, 1.55 V at
U0502-1
• Absence of signal may indicate
failure with Q0503
• Absence of signal may indicate
failure with U0500, U0950, or
U0951 (9 V Regulators)
• Absence of signal may indicate
failure with U0503, U0962,
U0501, U0507, or U0502 (5 V,
3 V, 2.85 V, 1.85 V, and 1.55 V
Regulators)
Flex/Control Head Check for SW_B+_CH at J0401-
33,34, TP0413, or pin 21 of P502
(on control head)
Absence of signal may indicate
failure with flex, control head
Clocks
Flex, Control Head
Check for 32 kHz clock at
U0102-4, and 16.8 MHz clock at
C0106, C0911
Check for SSI signal on CH.
Presence of signals may indicate
failure with U0001
(Microprocessor Board).
Absence of signals may indicate
failure with U0102 (Inverter) or
with FGU reference oscillator
circuit
No signal indicate missing/failure
of SSI components (MUXes,
jumper resistors) on CH board,
flex contamination or failure.
Needs rework or changing of
flex.
No RX Audio/
Receive Does not
Unsquelch
Controller Block (Inject 1 kHz tone, 3 kHz
deviation into radio antenna, set
volume to rated audio.
• Check for speaker leads
shorted to ground, or at U0204-
4, 6.
• Check for > 30 mV rms audio
at audio PA input, U0204-1,9.
• Check for > 30 mV rms audio
at U0206-8 or TP0205.
• Check for > 30 mV rms audio
at U0210-6 or U0200-2.
• Check that U0204-8 is >10 V
• Short may indicate failure with
VR0400, VR0412, or U0204
• Presence of signal may
indicate failure with U0204
(Audio PA)
• Presence of signal may
indicate failure with U0206
(Log-POT)
• Presence of signal may
indicate failure with U0210
(MUX); Absence of signal may
indicate failure with U0200
(CODEC), or U0001
(Microprocessor Board)
• Absence of >10V may indicate
failure with Q0200 or U0001
Regulators See description for No VOCON
Powerup
Table 5-3. XTL 1500 Troubleshooting Table (450-520 MHz) (Continued)
Symptom Check Section Troubleshooting Procedure Component