NAD-T973_MKIIA-pwr-sm 维修电路原理图.pdf

SERVICE MANUALSERVICE MANUALT973 C/AHT973 MKII-A MODEL: T973SERVICE MANUAL NAD 2008NAD ELECTRONICS INTERNATIONALTORONTOT973C/AHSEVEN CHANNEL AMPLIFIERT973C/AHSEVEN CHANNEL AMPLIFIERWITH STANDBY BOARD ADDENDUM SEVEN CHANNEL AMPLIFIERWITH STANDBY BOARD ADDENDUMRadioFans.CN 收音机爱 好者资料库ALIGNMENT PROCEDURE (T973) 2004 2005 A. DC OFFSET VOLTAGE The DC OFFSET between OFFSET Test Point and AGND must be controlled within 0+/-3mV. If its found to be out of this range, change the TL084BCD to get it to meetthe requirement. B. IDLING CURRENT The idling current at the final stage of the unit should be set to about 40mA+/-10mA. Adjust RV102 (As marked as “Idling Current ADJ” in the enclosed drawing below) to control the voltage between Idling current Test point 1 and 2 to be 8mV +/- 2mV. Preheat the unit for 10 to 15 minutes, and then readjust to 8mV +/- 2mV. (Please note: The idling current must be adjusted when all modules are assembled into the unit.) C. ISC SENSITIVITY Adjust Pot RV104 (as marked as “ISC SENS ADJ” in the below drawing) to get the voltage across “ISC SENS TEST POINT” and AGND to be 0mV+/-10mV. (Please note that the ISC should be adjusted when all modules are assembled into the unit. Its not possible to get 0V +/-10mV if the modules are not assembled. D. THERMAL SENSE ADJUSTMENT The adjustment should be always done when the T973 is cool condition. (That means the temperature inside the unit should be almost same as the ambient temperature. Connector P208B that connects the transformer and power board should be removed to avoid that the Idling current to heat up the unit excessively) At ambient temperature of 25 C degree and when the unit is just turned on (still in cool condition), adjust the pot RV103 (as marked as “THERMAL SENS ADJ” in the below drawing) to get voltage across the THERMAL TEST POINT and AGND to be 750mV +/-10mV. While the ambient temperature is different, the voltage will vary as well. There is a relation between the temperature and voltage, that is; if the ambient temperature is 20 degree C, the voltage should be 850mV+/-10mV; if the ambient temperature is 30 degree C, the voltage should be adjusted to 650mV+/-10mV, etc. E. Fan Cut Off Point Adjustment Note: This Fan cut off function does not appear on PCB V10.0, V11.0 or MKII-A version but only appeared on PCB V12.0. Run the unit for all 7 channels at 1 kHz, 4ohms load, and 250mW output. Do this adjustment when the unit heats up, for example; run the unit at all 7 channels at 50W/4ohms for 10 minutes. Then adjust Pot RV201 on power supply board so the voltage at Pin14 of IC203 just changes from negative to positive (to get the fans just start turning). Then turn off the input signal and monitor if fans will stop within 30 seconds, then turn on the input signal again to see if the fans start turning immediately. Page 2RadioFans.CN 收音机爱 好者资料库ALIGNMENT PROCEDURE (T973) 2006 T973 MKII-BA. THERMAL SENSE ADJUSTMENT Always perform this adjustment when the T973 is in a cool condition such that the temperature inside the unit should be almost same as the ambient temperature. For this adjustment, first disconnect the plug from connector P208B that connects the transformer and power board in order to avoid the idle currents of the amplifiers from heating up the T973 excessively. At an ambient temperature of 25 degrees C and when the unit is just turned on, adjust the potentiometer RV103 (as marked as “Thermal Sens ADJ” in Figure 1) for a reading of 750mV+/-10mV across the THERMAL TEST POINT and AGND. After all THERMAL SENSE adjustments are complete, reattach the plug to connector P208B. NOTES: There is an inverse relation between the temperature and voltage. At different ambient temperatures, the THERMAL TEST POINT voltage should vary. For example; for an ambient temperature is 20 degrees C, the THERMAL TEST POINT voltage should be 850mV+/-10mV, and for an ambient temperature is 30 degrees C, the THERMAL TEST POINT voltage should be adjusted to 650mV+/-10mV. Ambient Celsius Ambient Fahrenheit THERMAL TEST POINT & AGND 20 68 850mV +/- 10mV 25 77 750mV +/- 10mV 30 86 650mV +/- 10mV B. DC OFFSET VOLTAGE The DC OFFSET between OFFSET TEST POINT and AGND must be servo-controlled within 0+/-3mV. If the values are found not to be within this range, change the TL084BCD to meet the specification. C. IDLING CURRENT The idle current at the final stages of each power amplifier module should be set to 40mA+/-10mA. Measure a reading of 8mV +/- 2mV between IDLING CURRENT TEST POINTS 1 and 2. Adjust RV102 (As marked as “IDLING CURRENT ADJ” in Figure 1) after preheating the unit for 10 to 15 minutes without any input/output connections, and then readjust to 8mV +/- 2mV. Notes: The idle current must be adjusted with all modules assembled into the unit. The 10 to 15 minutes preheating of the unit represents powering on the unit for 10 to 15 minutes without any connections of input signals or loads. D. ISC SENSITIVITY The ISC current-sensing voltage under a non-signal condition should be 0mV+/-50mV. Adjust Potentiometer RV104 (as marked as “ISC SENSE ADJ” Figure 1) for a reading of 0mV+/-10mV between the “ISC SENSE TEST POINT” and AGND. Note: The ISC should be adjusted when all modules are assembled into the unit. It is not possible to get the 0mV +/-10mV if any of the modules are removed. Page 3 ggggggggggggggggggggggggggggggggggggggggggggggggISC Adjustment (MK I & MK IIA)Idle Current Adjustment (MK I & MK IIA)ggggggggggggggggggggggggggggggggggggggggggggggggIdle Current Adjustment (MK IIB 2006)ISC Adjustment (MK IIB 2006)Page 4T 973 WIRING DIAGRAMPage 5AGND4-62V_4+62V_4AGND4+62V_4AGND4-62V_4AGND4PROT6DGNDSTBYDGNDPROT3SCLEDPROT4PROT7SCLEDPROT5+8VPROT1PROT2STBYAGND+8V-68V+68VDGNDAGNDACOFF+18VFAN2-18VFAN3FAN1+8VAGND6+62V_3AGND6-62V_3AGND6+62V_3DGNDSCLEDSCN_3SCN_4SCP_4+62V_3SCP_3-62V_3-62V_4+62V_4-68VSCN_3+18VACOFF-18V+68VPROT5SEN5SCP_3-68VSCN_3+18VACOFF-18V+68VPROT6SEN6SCP_3-68VSCN_3+18VACOFF-18V+68VPROT7SEN7SCP_3AGND6B+62V_3B-62V_3B-62V_3BAGND6B+62V_3BAGND6A+62V_3A-62V_3A-62V_3AAGND6AAGND6A+62V_3A+62V_3-62V_3-62V_3AGND6AGND6+62V_3-68VSCN_4+18VACOFF-18V+68VPROT1SEN1SCP_4AGND4A+62V_4A+62V_4A-68VSCN_4+18VACOFF-18V+68VPROT2SEN2SCP_4AGND4B+62V_4B-62V_4BAGND4B-68VSCN_4+18VACOFF-18V+68VPROT3SEN3SCP_4AGND4+62V_4-62V_4-62V_4AGND4+62V_4+62V_4-62V_4-62V_4AGND4AGND4+62V_4-68VSCN_4+18VACOFF-18V+68VPROT4SEN4SCP_4STBYAGNDSEN2SEN3SEN5ISCTRIG_6ISCTRIG_7SEN1ISCTRIG_5ISCTRIG_3ISCTRIG_2AGND6BAGND6FAN1DGNDDGNDFAN2DGNDFAN3+62V_3+62V_3B+62V_3A-62V_3-62V_3B-62V_3AAGND6AGND6BAGND6AISCTRIG_1ISCTRIG_3ISCTRIG_5ISCTRIG_6ISCTRIG_7ISCTRIG_1SEN6SEN7DGNDISCTRIG_4SEN4AGND4AAGND4A-62V_4A-62V_4AISCTRIG_2AGND4B-62V_4B+62V_4BAGND4ISCTRIG_4AGND4-62V_3AGND6AGND4AAGND4BAGND4-62V_4A-62V_4B-62V_4+62V_4A+62V_4B+62V_4SCHEMATIC DIAGRAM(AMP CONNECTION)1122334455667788991010P603BS10B-PH-SM3-TBP603BS10B-PH-SM3-TB1122P622HEADER 2P622HEADER 2BUS606COPPER STRIPBUS606COPPER STRIP112233445566778899P608BMOLEX 2145/3215 TOP ENTRY/9PINP608BMOLEX 2145/3215 TOP ENTRY/9PIN1122P623HEADER 2P623HEADER 2112233445566778899P615BMOLEX 2145/3215 TOP ENTRY/9PINP615BMOLEX 2145/3215 TOP ENTRY/9PIN123456789101112P618BMOLEX 51021/12PIN/500mm WIREP618BMOLEX 51021/12PIN/500mm WIRE112233445566778899P609BMOLEX 2145/3215 TOP ENTRY/9PINP609BMOLEX 2145/3215 TOP ENTRY/9PINBUS603COPPER STRIPBUS603COPPER STRIP112233445566778899P616BMOLEX 2145/3215 TOP ENTRY/9PINP616BMOLEX 2145/3215 TOP ENTRY/9PIN112233445566778899P610BMOLEX 2145/3215 TOP ENTRY/9PINP610BMOLEX 2145/3215 TOP ENTRY/9PIN13579111315246810121416P601BMOLEX 52207 RIGHT ANGLE/SMT/ZIF/TOP CONTACT STYLE/16PINP601BMOLEX 52207 RIGHT ANGLE/SMT/ZIF/TOP CONTACT STYLE/16PIN112233445566778899P604BMOLEX 2145/3215 TOP ENTRY/9PINP604BMOLEX 2145/3215 TOP ENTRY/9PINBUS601COPPER STRIPBUS601COPPER STRIP1122334455667788P619BMOLEX 5145-NCH TOP ENTRY/8PINP619BMOLEX 5145-NCH TOP ENTRY/8PIN112233445566778899P617BMOLEX 2145/3215 TOP ENTRY/9PINP617BMOLEX 2145/3215 TOP ENTRY/9PIN112233445566778899P611BMOLEX 2145/3215 TOP ENTRY/9PINP611BMOLEX 2145/3215 TOP ENTRY/9PIN112233445566778899P605BMOLEX 2145/3215 TOP ENTRY/9PINP605BMOLEX 2145/3215 TOP ENTRY/9PIN112233445566778899P612BMOLEX 2145/3215 TOP ENTRY/9PINP612BMOLEX 2145/3215 TOP ENTRY/9PIN112233445566778899P606BMOLEX 2145/3215 TOP ENTRY/9PINP606BMOLEX 2145/3215 TOP ENTRY/9PIN13579111315246810121416P602BMOLEX 52207 RIGHT ANGLE/SMT/ZIF/TOP CONTACT STYLE/16PINP602BMOLEX 52207 RIGHT ANGLE/SMT/ZIF/TOP CONTACT STYLE/16PINBUS602COPPER STRIPBUS602COPPER STRIP112233445566778899P613BMOLEX 2145/3215 TOP ENTRY/9PINP613BMOLEX 2145/3215 TOP ENTRY/9PIN112233445566778899P607BMOLEX 2145/3215 TOP ENTRY/9PINP607BMOLEX 2145/3215 TOP ENTRY/9PINBUS604COPPER STRIPBUS604COPPER STRIP112233445566778899P614BMOLEX 2145/3215 TOP ENTRY/9PINP614BMOLEX 2145/3215 TOP ENTRY/9PIN1122334455667788P620BMOLEX 5145-NCH TOP ENTRY/8PINP620BMOLEX 5145-NCH TOP ENTRY/8PIN1122P621BHEADER 2P621BHEADER 2BUS605COPPER STRIPBUS605COPPER STRIPPage 6 STBY+62V_4+68VSEN5+18VSEN3STBYLEDSEN1SEN2-62V_4SEN3SEN7+5VDSEN6SEN4SEN5-18V+8VISCTRIG1.7ACOUTRELAYACINISCTRIG_2PROT3-68VFAN1SEN2ISCTRIG_7DGNDSCLEDSTBYAGND4FAN2SEN5+18V+68VISCTRIG_6ISCTRIG_7ISCTRIG_3SEN7ISCTRIG_1AGND4-18VACOFFAGND6+8VSEN3-68V-62V_3AGND6-62V_4AGND4FAN3SEN6SCLEDISCTRIG_4FAN1PROT4+8VDGNDISCTRIG_4DGNDPROT7ISCTRIG_1ISCTRIG_6+62V_3PROT2+62V_4-62V_4AGND4DGNDISCTRIG_2ISCTRIG_5STBY+62V_4SEN4SEN1FAN2+62V_3AGND6PROT6PROT5ISCTRIG_5FAN3PROT1AGND6ISCTRIG_3+62V_3-62V_3DGNDDGNDPROT7PROT3PROT2PROT4+5VDPROT5PROT1PROT6DGNDSCLEDDGND+12VDSTBYLED-62V_3ACOFF+68V-62V_4-18V-68V-62V_3+18V+62V_3+62V_4ACOFF+12VD-12VD-12VD+12VD+12VD+12VD+12VD+12VD+12VD+12VD+12VD+12VD+18V+18VFOR Q202FOR BR205&QT02FOR IC205FOR IC202FOR Q201FOR BR204&QT01FOR Q205FOR Q220FOR Q206FOR Q219FOR BR206&QT03CONNECT TO PROTECT ANDSOFTCLIPPING LED BOARDFOR QT04FOR Q218/1/2W/50V/80V/80V/1/2W/1/2W/1/2W/1/2W/1/2W/1/2W/1/2W/1%/1%/1%/1%/1%/1%/1%/1%/1%/1%/1%/1%/50V/50V/50V/50V/100V/100V/100V/100V/100V/100V/100V/100V/100V/100V/100V/1KV/100V/100V/100V/100V/100V/1KV/100V/100V/25V/25V/25V/25V/25V/25V/250V/250V/80V/250V/80V/50V/25V/1/2WFP/1/2WFP/100V/100V/1%/1%/1%/250V/250V/250V/250V/250V/250V/100V/250V/250V/250V/250V/80V/80V/100V/100V/100V/50V/100V/100V/100V/100V/100V/100V/100V/100VFOR IC201CONNECT TO AMP MODULE VIA CONNECTION BOARD/1/4W/1/4W/1/2W/1/2W/1/2W/1/2WHS20170-010003-0HS20170-010003-0D2154.3VD2154.3VHS20270-010003-0HS20270-010003-0D2134.3VD2134.3VC20510nC20510nC274100nC274100nR2021KR2021KR2071.5KR2071.5KO3I1G2IC201LM7812IC201LM7812R2011KR2011KR29210KR29210KR2251KR2251KQ2082SC1775Q2082SC1775R283N.I.R283N.I.R2571KR2571KR26310KR26310KC22310nC22310nD2041N4148D2041N4148+C23247u+C23247uR29510KR29510KQ2112SA1015Q2112SA1015C2502.2nC2502.2n+C215100u+C215100uQ2272SD667Q2272SD667G1O3I2IC202LM7912IC202LM7912C229100nC229100nQ2102SC1815Q2102SC1815C20410nC20410n312QT0230TPS08QT0230TPS08HS21370-010003-0HS21370-010003-0C22210nC22210nQ2172SD667Q2172SD667C22110nC22110n+C216100u+C216100uR26910KR26910K+-BR202DB104+-BR202DB104D2164.3VD2164.3VR206100R206100R254470R254470C206100nC206100n+C23310u+C23310u123456789101112P206B12P2.54-CP206B12P2.54-CR26410KR26410K+C20810u+C20810uR28010KR28010KC275100nC275100n+C225*1000u+1000uR273100R273100+C2143900u+C2143900u+-BR204KBJ2506+-BR204KBJ2506C22010nC22010nR2371KR2371KR226220R226220Q2142SC1815Q2142SC1815Q219KSC2690AYSQ219KSC2690AYSQ205KSC2690AYSQ205KSC2690AYSQ221N.I.Q221N.I.R28510KR28510KR26810KR26810KR2911KR2911K1122334455667788P201AHEADER 8P201AHEADER 8R282N.I.R282N.I.+C24010u+C24010uD2021N4148D2021N4148D2144.3VD2144.3VC2512.2nC2512.2nF203T1.25AL/250VF203T1.25AL/250V+C247*15000u+C24715000uQ2032SC1815Q2032SC1815R23410KR23410KR2551KR2551KC24210nC24210nR2042.2KR2042.2KHS20670-010003-0HS20670-010003-0321411+-IC203ATL084+-IC203ATL084C25810nC25810nR21310R21310R27243KR27243KR28110KR28110K+C23510u+C23510uR22712KR22712KR2161KR2161KR29710KR29710KR2221KR2221KR26610KR26610K+C20910u+C20910uR23310KR23310KD2051N4148D2051N41481122334455667788P202AHEADER 8P202AHEADER 8Q218KSC2690AYSQ218KSC2690AYS+C21747u+C21747uR23847R23847R2783.3KR2783.3KR28810KR28810KC2462.2nC2462.2nC2522.2nC2522.2nR205100R205100D2125.1VD2125.1VR23210KR23210KR24047R24047Q2242SC1815Q2242SC18151234P207B4P2.54-CP207B4P2.54-CBUS204COPPER STRIPBUS204COPPER 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