2.2 Fuses F501, F502 Blow
2.2-1 Disconnect drivers, and repeat test per 2.1-4. Signal
at test point (G) now should be around .5V.
2.2-2 Measure resistance of voice coils in drivers. Should
be 6.6 ohm each, 3.3 ohm in parallel.
2.3 Automatic ON/OFF
This can also be checked with the same setup as in 2.1-4.
2.3-1 Set toggle switch in position "AUTO".
2.3-2 Signal at test point (H) should be clipped and measure
7 V peak to peak. (Oscilloscope) Signal at test point
(I) should be about 20 V DC.
2.3-3 Shunt R210 by 100k ohm to shorten off - delay.
Check that ON is actuated when signal from generator
exceeds .5mV at 500Hz.
2.4 B2-50 Oscillates Between ON and OFF with no audio signal
on input.
2.4-1 Check DC offset at test point (G). Should be between
+10mV and +100mV.
If DC offset is outside these limits, fault can be in
C414 or in the Power Amplifier. (See also section 1.1).
NOTE: If a large DC voltage has appeared at the output of the
Power Amplifier (caused by a fault), C414 will probably
be damaged, and it should be replaced.
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