Motorola ASTRO Digital Spectra Service Manual

5-22 Troubleshooting Charts
October 28, 2002 6881076C25-D
Chart C.28 ASTRO Spectra Plus VOCON TX Modulation Failure Sheet 2 of 4
A
C
Inspect U201
OK?
Repair component
Measure waveform at U201-39
should match Figure 6-12
Waveform
correct?
Inspect R200,
R201, and C201
Repair components
OK?
Repair oscillator
circuit
16.8MHz
Clock
Check SSI connections per
Figure 5. U201-35 = STD - T1
U201-34 = FS -T2
U201-33 = SCK - T3
OK?
Check SPI connections per
Figure 6. U201-44 = ADDAG_SEL
-T1
U201-43 = QSCKA - T2
U201-42 = MOSIA - T3
U201-41 = MISOA - T4
Inspect U201-
35, 34, 33
OK?
OK?
OK?
OK?
OK?
Inspect U201-
41, 42, 43, 44
Measure wavefoorm at U402-17,
should match Figure 6-17
Repair U201
Repair U201
Check SAP connections per
Figure 8. U402-7 = FS -T1
U402-11 = DCLK - T2
U402-13 = TXD - T3
U402-10 = PWRD - T4
OK?
OK?
Replace U201
Check Patriot supplies
L300 - T1 -3.0V
L301 - T2 - 1.8V
Repair regulator
circuit
Check Patriot clocks
C326 - T1 - 16.8MHz
R428 - T2 - 32kHz
Inspect and repair
Patriot IC - U300
Repair proper clock
circuit
Yes
No
Yes
No
Yes
No
Yes
No
No
Yes
Yes
No
No
Yes
No
Yes
Yes
No
No
Yes
No
Yes
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Motorola ASTRO Digital Spectra Specifications

General

Brand	Motorola
Model	ASTRO Digital Spectra
Category	Radio
Language	English