Inspections - Yamaha P 1000S Service Manual

P1000S/P2500S/P3500S

INSPECTIONS

1. Scope
This inspection specifications is applied to the power amplifier P1000S/P2500S/P3500S.
*Refer to "the switch and adjustment part" of the page 34 of the text for a switch and an adjustment place.
2. Preparation for STEREO/PARALLEL mode
Attenuator
Input terminal
MODE switch
SUB WOOFER/LOW CUT switch
YS Processing switch
HPF switch
Load resistor
Unless otherwise specified, the operation shall be both channels drive.
DIN AUDIO filter shall be used for the noise level measurements.
Unless otherwise specified, the input signal shall be high quality sine wave.
3. Inspection and Adjustment
3.1 POWER LED, PROTECTION LED and Power on muting time
POWER LED and PROTECTION LED shall light when the POWER switch is turned on.
2.5 +/- 1 seconds after the power switch is turned on, PROTECTION LED shall lights off.
3.2 Fan and TEMP LED
The fan shall operate when short circuit on the two jumper wires that mounted of DC circuit board marked "FAN-C".
The TEMP LED shall lights up when short circuit on the two jumper wires that marked "TM-C".
3.3 Idle current
Connect the input terminal to the GROUND and adjust VR101(A channel) and VR102(B channel) that the DC voltage
of Vb between the pin1 and pin2 of CN108(A channel) and the CN107(B channel) shall be 0.5 +/- 0.1 mV.
After finishing all inspections, adjust the Vb again to 0.5 +/- 0.1 mV.
3.4 DC Voltage of output terminal
Connect the input terminal to the GROUND and measure the DC voltage Vdc of the output terminal shall be 0 +/- 75 mV.
3.5 Gain
The output voltage should be +22.1 +/- 0.5 dBu when input signal is 1 kHz, -10.0 dBu.
This inspection shall be performed on PARALLEL mode.
Don't feed input signal to channel B on PARALLEL mode.
Set the input attenuator to -10 dB.Input signal is 1 kHz, -10 dBu.
The output voltage shall be +12.0 +/- 3.0 dB.
3.6 Frequency response
Input signals are each 20 Hz, 1 kHz and 20 kHz, -10 dBu.
The output voltage shall be 0.0 +/- 0.5 dB at 20 Hz, -0.5 +/- 0.5 dB at 20 kHz compared to the 1 kHz.
<Set MODE switch to PARALLEL.>
The inspection process of SUB WOOFER and LOW CUT position as follows.
1) channel A
2) channel A
3) channel B
4) channel B
26
"0" (MAX)
cannon connector 2PIN-HOT/3PIN-COLD/1PIN-GND
STEREO
OFF (except P1000S)
OFF (except P1000S)
OFF (P1000S only)
8 ohms +/- 1 %
25 Hz
150 Hz
25 Hz
150 Hz