Yamaha XP7000, Руководство по обслуживанию

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XP7000/XP5000
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3.11 Protection circuit
Disconnect the load resistance from the output terminal.
Short-circuit 2 jumper cables within the “DC-C” marked frame of the PS circuit board and check that the power is shut down
within 2 seconds.
After checking, make short-circuited jumper cables off. Turn off the power and turn it on again 3 seconds later to check that the
unit can be restarted normally.
3.12 Efficiency
(1) Input a 1 kHz, -6.6 dBu signal and measure the primary power.
Check that the measured value is within the range specified in the table below.
3.10 Stability
Use only the polyester film capacitor of net capacity of 0.01 uF as a load.
Input the 1 kHz, -10 dBu rectangular square wave and check that no oscillation occurs and following conditions are satisfied.
Overshoot : Vp/Vo<2.5
Ringing : Converged within 7 waves and no oscillation generated
··· Ringing Waves
Vo
Vp
3.13 VI limiter and comp.
Connect 1 ohms (
±
5%) load to the output terminal and input a 1 kHz, -1.5 dBu signal. Check that the output voltage is within
the range specified in the table below. Also check that the distortion is 5% or less and the CLIP LED lights up.
Perform this inspection on each channel separately.
This inspection should be completed within 30 seconds.
XP5000
140 +/- 30 W
XP7000
140 +/- 30 W
XP5000
35 +/- 10 W
XP7000
35 +/- 10 W
XP5000
16 +/- 4 V
XP7000
18 +/- 4 V
(2) Shunt 2 pin (hot) and 3 pin (cold) of input terminals with 600 ohms and measure the primary power. Check that the
measured value is within the range specified in the table below.
3.14 SIGNAL LED
Input a 1 kHz, -23 dBu sine wave signal and check that the SIGNAL LED lights up. Perform this inspection on each channel
separately.