Denon AVR-S510BT Service Manual page 43

4.2. Power AMP (MAIN UNIT)
No sound is output.
The protector operates.
YES
Is the power transistor open or short-
circuited?
2SB1560/2SD2390
NO
Is the emitter resistance of the power
transistor open?
0.47 Ω
NO
Is the base resistance of the power
transistor open?
4.7 Ω
NO
Is the trimmer potentiometer between the
base of the power transistor open?
1k Ω
NO
Is other transistor trouble?
NO
Is other resistance trouble?
NO
Turn on the power, check that voltage of the section is normal and that idling electric current is
flowing.
YES
Replace the power transistor.
YES
Replace the emitter resistance.
YES
Replace the base resistance.
YES
Replace the trimmer potentiometers.
YES
Replace the transistor.
YES
Replace the resistance.
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