Philips PTV800, Руководство по обслуживанию

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No 130 volt supply
1.
With 120 volts ac applied, ground Pin 16 of IC402 to bypass the microprocessor. If the
full power supply turns on, troubleshoot the microprocessor and reset circuit.
2. Monitor the voltage between Pins 1 and 2 of IC406 as Pin 16 of IC402 is grounded. The
voltage should equalize between these two Pins as Pin 8 of IC402 turns Off. If no change
occurs, check IC406, IC402, and C454.
3. Check the 130 volt supply line for a short circuit.
4. Monitor the 130 volt supply line with an Oscilloscope for a change as the set is turned On.
If the supply comes up and then shuts down, check Pin 7 of IC402 as the set is turned
On. If no change occurs at Pin 7, check R453. If the voltage changes at Pin 7 of IC402,
then check IC402, F409, R450, R451, and R452.
5. If IC406 turns Off, then check Pin 13 of IC401 for a voltage less than 2.5 volts. If this
voltage is above 2.5 volts, check the voltage between Pins 2 and 3 of IC405. If this
voltage is approximately 1.5 volts, change IC405.
6. If Pin 13 of IC401 is lower than Pin 12, check the output on Pin 10 of IC401, Q401 and
related components.
7. If the 130 volt supply is present, troubleshoot the sweep circuits.