Rf Board Troubleshooting; Display Flashes "Fail 001; Table 4-2. Voltage By Location - Motorola ASTRO Digital Spectra Plus Service Manual

Troubleshooting Procedures: ASTRO Spectra Procedures
12. Power-up the EMC (if it is enabled in the codeplug).
13. Turn off the green LED.
14. Start up operating system.
15. Display for one second:
- "SELF TEST" for the W3, model.
- "SELF CHK" for the W4, W5, and W7 models.
- "SELF CHECK" for the W9 models.
16. Turn off the green LED in the W3 model, or the TX and Busy LEDs in the W4, W5, W7, and
W9 models.
Display errors if a fatal error exists at this time.
4.1.4

RF Board Troubleshooting

This information will help you troubleshoot the ASTRO Spectra Radio RF board. Use this
information, along with the Theory of Operation, to diagnose and isolate the cause of failures. The
principal tools needed to troubleshoot a circuit to the component level are the schematic and the
Theory of Operation.
In addition to the schematic and theory, the following troubleshooting information identifies tests and
checks designed to help isolate problems.
Prior to troubleshooting, it is important to review the Theory of Operation, including specific
precautions and troubleshooting methods. Because much of the radio's circuitry operates at high
frequencies, measurements must be taken very carefully. Notes and cautions are added to the text
to alert the reader to this need in areas of greatest sensitivity. However, the need for extreme care
does exist in all measurements and tests.

4.1.4.1 Display Flashes "FAIL 001"

This display indicates a synthesizer "out-of-lock" condition. Check the dc power supplies for the
correct voltages at the following locations:
VOLTAGE
+5 Vdc
+8.6 Vdc
+5 Vdc
+3.25 Vdc
1. If any of the dc voltages are not correct, troubleshoot the source of the supplied power and
correct the problem. If the voltages are correct, continue with the following checks.
2. Check U602, pin 19 for reference frequency, 0- to 9-V, square wave. If not correct, go to
"Incorrect Values at U602, pin 19"; otherwise, continue with the following checks.
3. Check U602, pin 25 for reference frequency, 0- to 9-V, square wave. If not correct, go to
"Incorrect Values at U602, pin 25 (MODULUS CONTROL)"; otherwise, continue with the
following checks.
4. Check the negative steering line, J601, pin 4. If correct, continue with the following checks.
6881076C25-D

Table 4-2. Voltage by Location

LOCATION
Q602 Collector
Q603 Collector
J500 pin 1 Power from command board to
J500 pin 2 reference oscillator
REMARKS
4-5
October 28, 2002