ONKYO TXNR900
Service Manual

TX-NR900/E ADJUSTMENT AND CONFIRMATION PROCEDURES 1
Idling current adjustment Before Idling current adjustment, turn the trimming resistors R6040 to R6046 to counter-clockwise. Connect the DC voltmeter at the sockets P6080 to P6086. After turn POWER to ON, adjust the trimming resistors R6040, R6041 and R6042 so that the reading of voltmeter becomes 11 mV. (Front and center channels) Adjust the trimming resistors R6043, R6044, R6045 and R6046 so that the reading of voltmeter becomes 4.5 mV. (Surround and surround back channels) After adjustment, attach the top cover. Confirm the voltage of points above after about five minutes. Front and center channels When less than 16.5 mV, readjust the resistors above so that the voltage becomes 16.5 mV. When 16.5 mV to 18.5 mV, you are not necessary to adjust. When more than 18.5 mV, readjust the resistors above so that the voltage becomes 18.5 mV. Surround and surround back channels When less than 6.0 mV, readjust the resistors above so that the voltage becomes 6.0 mV. When 6.0 mV to 8.0 mV, you are not necessary to adjust. When more than 6.0 mV, readjust the resistors above so that the voltage becomes 8.0 mV. Note: No load and No signal

R6040

P6080 IDID+ P6001

R6041

P6081 IDID+ P6011 P5003B

R6042

P6082 IDID+

P6000

P6010

P6002 P5003C

P6012

P5003A P6205

P5004A P6013 ID+ IDP6083

P5004B P6003 BIAS ID+

P6004 BIAS

P5004C P6015 BIAS R6045

P6005 P5004D P6016 ID+ ID-P6086 BIAS R6046

P6006

R6043

ID-

P6084

R6044

ID+ ID- P6085

NCAF-7706

Confirmation of protection circuit 1. Confirmation of operation of speaker relay Confirm that the speaker relays turn ON approximate. 5 seconds after the power switch is turned ON. Confirm that the speaker relays turn OFF immediately after the power switch is turned OFF. 2. Confirmation of DC detection circuit Press and hold down CD button, then press STANDBY/ON and DISPLAY buttons to set the unit to "Test-1" mode. After "Test-1" on the FL tube light on, press VIDEO 1 button to set the unit to "Test-1-00". Apply DC 1.5 to 3.5V to the MULTI-CH INPUT terminal with no load. Confirm that the speaker relay turns OFF. Apply DC -1.5 to -3.5 V to the MULTI-CH INPUT terminal with no load. Confirm that the speaker relay turns OFF. Caution: Don't apply DC voltage more than 1 sec..