1.97K-9636 1.69K-545 Printed in Japan '99.1 CONTENTS SPECIFICATIONS .................................................................. 3 PANEL LAYOUT .................................................................... 4 DIMENSIONS ........................................................................ 5 BLOCK DIAGRAM ................................................................. 5 CIRCUIT BOARD LAYOUT & WIRING .................................. 6 DISASSEMBLY PROCEDURE ............................................... 7 IC BLOCK DIAGRAM .............................................................10 CIRCUIT BOARDS .................................................................11 INSPECTIONS .......................................................................13 PARTS LIST SERVICE MANUAL POWER AMPLIFIER XS250/350 PA 011440 www. xiaoyu163. com QQ 376315150 9 9 2 8 9 4 2 9 8 TEL 13942296513 9 9 2 8 9 4 2 9 8 0 5 1 5 1 3 6 7 3 Q Q TEL 13942296513 QQ 376315150 892498299 TEL 13942296513 QQ 376315150 892498299 http://www.xiaoyu163.com 2 XS250/350 IMPORTANT NOTICE This manual has been provided for the use of authorized Yamaha Retailers and their service personnel. It has been assumed that basic service procedures inherent to the industry, and more specifically Yamaha Products, are already known and understood by the users, and have therefore not been restated. WARNING: Failure to follow appropriate service and safety procedures when servicing this product may result in personal injury, destruction of expensive components, and failure of the product to perform as specified. For these reasons, we advise all Yamaha product owners that all service required should be performed by an authorized Yamaha Retailer or the appointed service representative. IMPORTANT: The presentation or sale of this manual to any individual or firm does not constitute authorization, certification or recognition of any applicable technical capabilities, or establish a principle-agent relationship of any form. The data provided is believed to be accurate and applicable to the unit(s) indicated on the cover. The research, engineering, and service departments of Yamaha are continually striving to improve Yamaha products. Modifications are, therefore, inevitable and changes in specification are subject to change without notice or obligation to retrofit. Should any discrepancy appear to exist, please contact the distributor's Service Division. WARNING: Static discharges can destroy expensive components. Discharge any static electricity you body may have accumulated by grounding yourself to the ground buss in the unit (heavy gauge black wires connect to this buss). IMPORTANT: Turn the unit OFF during disassembly and part replacement. Recheck all work before you apply power to the unit. WARNING: CHEMICAL CONTENT NOTICE! The solder used in the production of this product contains LEAD. In addition, other electrical/electronic and /or plastic (where applicable) components may also contain traces of chemicals found by the California Health and Welfare Agency (and possibly other entities) to cause cancer and/or birth defects or other reproductive harm. DO NOT PLACE SOLDER, ELECTRICAL/ELECTRONIC OR PLASTIC COMPONENTS IN YOUR MOUTH FOR ANY REASON WHAT- SOEVER! Avoid prolonged, unprotected contact between solder and your skin! When soldering, do not inhale solder fumes or expose eyes to solder/flux vapor! If you come in contact with solder or components located inside the enclosure of this product, wash your hands before handling food. www. xiaoyu163. com QQ 376315150 9 9 2 8 9 4 2 9 8 TEL 13942296513 9 9 2 8 9 4 2 9 8 0 5 1 5 1 3 6 7 3 Q Q TEL 13942296513 QQ 376315150 892498299 TEL 13942296513 QQ 376315150 892498299 http://www.xiaoyu163.com 3 XS250/350 •General Specifications XS250,XS350 Power Output Level (Rated Power) 8 ohm/STEREO 20 Hz~20 kHz 4 ohm/STEREO THD+N= 0.1% 8 ohm/BRIDGE 1 kHz 8 ohm/STEREO THD+N= 0.1% 4 ohm/STEREO 8 ohm/BRIDGE 1 kHz, 20 ms, no cilp 2 ohm/STEREO Power Bandwidth Half Power Total Harmonic Distortion (THD+N) 4–8 ohm/STEREO 20 Hz-20 kHz, Half Power 8 ohm/BRIDGE Frequency Responce 8 ohm, Po= 1 W Intermodulation Distortion (IMD) 4–8 ohm/STEREO 60 Hz: 7 kHz, 4:1, Half Power 8 ohm/BRIDGE Channel Separation Half Power, RL = 8 ohm, Vol. max., input 600 ohm shunt Residual Noise Vol. min. 12.7 kHz LPF IHF-A network SN Ratio Damping Factor 8 ohm, f= 1 kHz Slew Rate STEREO 8 ohm full swing BRIDGE Sensitivity (Vol.max.) Rated Power into 8 ohm Voltage Ggin (Vol.max.) Input Impedance Controls Front Panel Rear Panel Connectors Input Output Indicators POWER PROTECTION CLIP SLGNAL Protection Circuits PC limiter Fan Speed Power Requirements US & Canada Europe Other Power Consumption Idling 1/8 output power, 4 ohm Maximum output, 4 ohm Dimentions (W x H x D) Weight 170 W + 170 W 250 W + 250 W 500 W 185 W + 185 W 280 W + 280 W 560 W 400 W + 400 W 10 Hz–40 kHz (THD+N= 0.1%) 230 W + 230 W 350 W + 350 W 700 W 250 W + 250 W 400 W + 400 W 800 W 600 W + 600 W POWER switch (ON/OFF) Volume (31 position)x 2 Mode switch (STEREO/BRIDGE/PARALLEL) Filter switch (OFF/SUBWOOFER/LOW CUT)x 2 (-12 dB/oct.) Freq. control (25 Hz–125 Hz)x 2 Barrier strip terminal XLR-3-31 type/ch Barrier strip terminal 5-way binding posts Green x 2 (Red) x 2 (Red) x 2 (Green) POWER switch ON muting, DC detection, Temp. detection (heatsink temp >/– 90˚C) RL /–65 dB, 20 Hz–20 kHz /– -75 dB 100 dB >/–100 +/–30 V/µS +/–40 V/µS +1.7 dB +3.1 dB 32.1 dB 32.1 dB 30 k ohm/Balanced, 15 k ohm/Unbalanced 0 dB=0.775 Vrms, Half Power=1/2 Power Output Level (Rated Power) SPECIFICATIONS XS250 XS350 www. xiaoyu163. com QQ 376315150 9 9 2 8 9 4 2 9 8 TEL 13942296513 9 9 2 8 9 4 2 9 8 0 5 1 5 1 3 6 7 3 Q Q TEL 13942296513 QQ 376315150 892498299 TEL 13942296513 QQ 376315150 892498299 http://www.xiaoyu163.com 4 XS250/350 PANEL LAYOUT Front Panel Rear Panel POWER POWER SIGNAL CLIP SIGNAL CLIP PROTECTION CH A CH B ON OFF B-2 CHANNEL A-2 8-16Ω (BRIDGE) (–) (+) 4-8Ω/CHANNEL (STEREO) B-1 CHANNEL A-1 8-16Ω (BRIDGE) (–) – – + + (+) 4-8Ω/CHANNEL (STEREO) (BRIDGE) (PARALLEL) (BRIDGE) (PARALLEL) FILTER CHANNEL B CHANNEL A FREQ. FREQ. INPUT CHANNEL B CHANNEL A INPUT CHANNEL B CHANNEL A SPEAKERS G G MODE CHANNEL B CHANNEL A STEREO PARALLEL BRIDGE OFF LOW CUT SUB WOOFER OFF LOW CUT SUB WOOFER 20 15 10 6 3 0 –dB 00 40 30 25 90 125 150 Hz 25 50 90 125 150 Hz 25 50 20 15 10 6 3 0 –dB 00 40 30 25 – – + + 1 POWER switch and indicator 2 SIGNAL indicators 3 CLIP indicators 4 PROTECTION indicator 1 Frequency controls/Filter select switches (CHAN-NEL A,B) 2 Volume controls (CHANNEL A,B) 3 STEREO/BRIDGE/PARALLEL switch 4 SPEAKERS terminals 5 INPUT terminals 6 GND terminals 1 2 4 3 1 2 3 5 6 4 www. xiaoyu163. com QQ 376315150 9 9 2 8 9 4 2 9 8 TEL 13942296513 9 9 2 8 9 4 2 9 8 0 5 1 5 1 3 6 7 3 Q Q TEL 13942296513 QQ 376315150 892498299 TEL 13942296513 QQ 376315150 892498299 http://www.xiaoyu163.com 5 XS250/350 DIMENSIONS BLOCK DIAGRAM Unit: mm IC102 3 1 2 2 7 7 2 IC101 5 7 6 2 7 7 2 IC104 www. xiaoyu163. com QQ 376315150 9 9 2 8 9 4 2 9 8 TEL 13942296513 9 9 2 8 9 4 2 9 8 0 5 1 5 1 3 6 7 3 Q Q TEL 13942296513 QQ 376315150 892498299 TEL 13942296513 QQ 376315150 892498299 http://www.xiaoyu163.com 6 XS250/350 PA7 SUB 1/5 SUB 2/5 SUB 3/5 SUB 4/5 SUB 5/5 CIRCUIT BOARD LAYOUT & WIRING Top View Front View SUB 4/5 Wire color XS350 Only Power Transformer 3NC2-V294020 www. xiaoyu163. com QQ 376315150 9 9 2 8 9 4 2 9 8 TEL 13942296513 9 9 2 8 9 4 2 9 8 0 5 1 5 1 3 6 7 3 Q Q TEL 13942296513 QQ 376315150 892498299 TEL 13942296513 QQ 376315150 892498299 http://www.xiaoyu163.com 7 XS250/350 1. Top Cover 1-1 Remove the nine (9) screws marked [410]. The top cover can then be removed. (Fig. 1, 2) 2. Power Transformer 2-1 Remove the top cover. (See Procedure 1.) 2-2 Remove the four (4) screws marked [70]. The power transformer can then be removed. (Fig. 1) 5. Front Panel 5-1 Remove the top cover. (See Procedure 1.) 5-2 Remove the two (2) screws marked [380a] and the two (2) screws marked [380b]. The front panel can then be removed. (Fig. 3) 6. SUB 3/5 Circuit Board 6-1 Remove the top cover. (See Procedure 1.) 6-2 Remove the front panel. (See Procedure 5.) 6-3 Remove the two (2) screws marked [220]. The SUB 3/5 circuit board can then be removed. (Fig. 3) 1/5 2/5 3/5 4/5 3. SUB7 1/5 Circuit Board 3-1 Remove the top cover. (See Procedure 1.) 3-2 Remove the six (6) screws marked [80a]. The SUB 1/5 circuit board can then be removed. (Fig. 1) 4. SUB 2/5 Circuit Board 4-1 Remove the top cover. (See Procedure 1.) 4-2 Remove the six (6) screws marked [50a] and the two (2) screws marked [50b]. The SUB 2/5 circuit board can then be removed. (Fig. 2, 7) 7. SUB 4/5 Circuit Board 7-1 Remove the top cover. (See Procedure 1.) 7-2 Remove the front panel. (See Procedure 5.) 7-3 Remove the two (2) screws marked [200]. The SUB 4/5 circuit board can then be removed. (Fig. 3) 8. DC Fan 8-1 Remove the top cover. (See Procedure 1.) 8-2 Remove the front panel. (See Procedure 5.) 8-3 Remove the four (4) screws marked [150]. The DC fan can then be removed. (Fig. 3) [220]: Bind Head Tapping Screw-B 3.0X8 MFZN2BL (EP600190) 　　 [380]: Bind Head Tapping Screw-B 4.0X8 MFZN2BL (EG340190) 　　 [70] 4 [80a] 6 [410] [410] [410] [410] [410] [410] Top cover Power Transformer [410] Rear panel [380a] [380a] [380b] [380b] [50a] [50a] [50b] (Fig. 1) (Fig. 2) (Fig. 3) [200] [220] [150] [150] Front panel DC Fan [70]: Bind Head Screw SP 5.0X10 MFZN2BL (VU688100) 　　　 [80]: Bind Head Tapping Screw-B 3.0X8 MFZN2BL (EP600190) 　　　 [410]: Bind Head Tapping Screw-B 4.0X8 MFZN2BL (EG340190) 　　　 [50a]: Bind Head Screw A4.0X8 MFZN2BL (VP156800) [410]: Bind Head Tapping Screw-B 4.0X8 MFZN2BL (EG340190) 　　　 DISASSEMBLY PROCEDURE www. xiaoyu163. com QQ 376315150 9 9 2 8 9 4 2 9 8 TEL 13942296513 9 9 2 8 9 4 2 9 8 0 5 1 5 1 3 6 7 3 Q Q TEL 13942296513 QQ 376315150 892498299 TEL 13942296513 QQ 376315150 892498299 http://www.xiaoyu163.com 8 XS250/350 PA7 [60a]: Bind Head Screw SP 3.0X8 MFZN2Y (EG330290) 　　　　 [80b,c]: Bind Head Tapping Screw-B 3.0X12 MFZN2BL (VQ074600) 10. PA7 Circuit Board 10-1 Remove the top cover. (See Procedure 1.) 10-2 Remove the front panel. (See Procedure 5.) 10-3 Remove the PA7 unit. (See Procedure 9.) 10-4 Remove the sixteen (16) screws marked [80b]; the four (4) screws marked [80c] and the six (6) screws marked [60a]. The PA7 circuit board can then be removed. (Fig. 6) 9. PA7 Unit 9-1 Remove the top cover. (See Procedure 1.) 9-2 Remove the front panel. (See Procedure 5.) 9-3 Remove the four (4) screws marked [250]. The PA7 unit with the chassis can then be removed. (Fig. 4) 9-4 Remove the eight (8) screws marked [130]. The PA7 unit can then be removed. (Fig. 5) [130] (Fig. 4) (Fig. 5) (Fig. 6) [130] [130] [130] [60a] 4 [80c] 4 [80c] 4 [80b] 4 [80b] 4 [250] 4 [250]: Bonding Tapping Screw-B 4.0X8 MFZN2BL (VR779900) [130]: Bind Head Tapping Screw-B 4.0X8 MFZN2BL (EG340190) Holder A Holder A Isolation sheet A Isolation sheet A Heat Sink FAN Angle www. xiaoyu163. com QQ 376315150 9 9 2 8 9 4 2 9 8 TEL 13942296513 9 9 2 8 9 4 2 9 8 0 5 1 5 1 3 6 7 3 Q Q TEL 13942296513 QQ 376315150 892498299 TEL 13942296513 QQ 376315150 892498299 http://www.xiaoyu163.com 9 XS250/350 11. Rear Assembly 11-1 Remove the top cover. (See Procedure 1.) 11-2 Remove the six (6) screws marked [270]. The rear assembly can then be removed. (Fig. 7) 12. SUB 5/5 Circuit Board 12-1 Remove the top cover. (See Procedure 1.) 12-2 Remove the rear assembly. (See Procedure 11.) 12-3 Remove the four (4) screws marked [440] and the two (2) screws marked [50b] and the two (2) screws marked [60b]. The SUB 5/5 circuit board can then be removed. (Fig. 7) (Fig. 7) 2/5 5/5 [440] 2 Cover, Speaker terminal Rear panel [440] 2 [50a] 4 [50a] 2 [70b] 2 [60b] 2 [50b] 2 [50a]: Bind Head Screw A4.0X8 MFZN2BL (VP156800) [50b]: Bonding Tapping Screw-B 3.0X8 MFZN2BL (VN413300) 　　 [60b]: Bind Head Tapping Screw-B 3.0X12 MFZN2BL (VQ074600) 　　　 [70a]: Bind Head Screw SP 5.0X10 MFZN2BL (VU688100) 　　　 [70b]: Bind Head Tapping Screw-B 3.0X8 MFZN2BL (EP600190) 　　　 [440]: Bind Head Tapping Screw-B 3.0X8 MFZN2BL (EP600190) 　　　 [270] Rear assembly [270] [270] [270] [270]: Bonding Tapping Screw-B 4.0X8 MFZN2BL (VR779900) 　　 (Fig. 8) www. xiaoyu163. com QQ 376315150 9 9 2 8 9 4 2 9 8 TEL 13942296513 9 9 2 8 9 4 2 9 8 0 5 1 5 1 3 6 7 3 Q Q TEL 13942296513 QQ 376315150 892498299 TEL 13942296513 QQ 376315150 892498299 http://www.xiaoyu163.com 10 XS250/350 M5238AP (XM085A00) Operational Amplifier 1 2 3 4 -V 8 7 6 5 Output A +V Non-Inverting Input A -DC Voltage Supply +DC Voltage Supply Output B Inverting Input B Non-Inverting Input B Inverting Input A + - + - IC BLOCK DIAGRAM www. xiaoyu163. com QQ 376315150 9 9 2 8 9 4 2 9 8 TEL 13942296513 9 9 2 8 9 4 2 9 8 0 5 1 5 1 3 6 7 3 Q Q TEL 13942296513 QQ 376315150 892498299 TEL 13942296513 QQ 376315150 892498299 http://www.xiaoyu163.com XS250/350 XS250/350 XS250/350 SUB 1/5 Circuit Board SUB 2/5 Circuit Board SUB 3/5 Circuit Board SUB 4/5 Circuit Board SUB 5/5 Circuit Board •SX350 SUB(U) :3NA-V290000 2 SUB(H) :3NA-V290010 2 Components side Components side Components side Components side Components side CIRCUIT BOARDS from T101 to SUB 2/5-CN103 to PA-CN404 from T101 to SUB 1/5-CN610 to PA-CN201 to PA-CN301 from PA-W201 to PA-CN406 •SX250 SUB(U) :3NA-V289980 2 SUB(H) :3NA-V289990 2 11 w w w . x i a o y u 1 6 3 . c o m Q Q 3 7 6 3 1 5 1 5 0 9 9 2 8 9 4 2 9 8 T E L 1 3 9 4 2 2 9 6 5 1 3 9 9 2 8 9 4 2 9 8 0 5 1 5 1 3 6 7 3 Q Q TEL 13942296513 QQ 376315150 892498299 TEL 13942296513 QQ 376315150 892498299 http://www.xiaoyu163.com XS250/350 XS250/350 XS250/350 PA Circuit Board •SX350 3NA-V2899600 1 •SX250 3NA-V2899500 1 Components side to SUB 2/5-CN301 to SUB 1/5-CN611 from FAN to SUB 3/5-CN501 to SUB 2/5-CN101 12 w w w . x i a o y u 1 6 3 . c o m Q Q 3 7 6 3 1 5 1 5 0 9 9 2 8 9 4 2 9 8 T E L 1 3 9 4 2 2 9 6 5 1 3 9 9 2 8 9 4 2 9 8 0 5 1 5 1 3 6 7 3 Q Q TEL 13942296513 QQ 376315150 892498299 TEL 13942296513 QQ 376315150 892498299 http://www.xiaoyu163.com 13 XS250/350 A STEREO and PARALLEL Operation Before performing any following adjustments, set the unit as follows: 1. Set the ATTENUATIONS at the MAX. 2. Input terminal: Cannon connector pin 2 is HOT, pins 1 and 3 GROUND. 3. MODE switch: STEREO 4. Output terminal: RL = 4 ohm/more than 500 W 5. Others: Both Channel operation is required, if no particular indication. Moreover, turn off the filter switch, if no particular indication. Adjustment Specifications 1. Fan Test When turning on the power switch, confirm that both fans of right and left sides regulate at low speed. 2. Muting Test After applying power to the unit, the PROTECTION indicator should remain ON 2.5 +/-1 seconds to indicate that the protection circuitry is operating and the indicator should go out. NO signal is output while this indicator lit. 3. Idle Current Test Connect the input terminal to the GROUND and adjust the VR201 (A channel) and VR301 (B channel) that the DC voltage Vb between the pin 1 and pin 2of the CN202 (A channel) and the CN302 (B channel) should be 1.0 +/-0.2 mV. And After finishing all tests, adjust the Vb again to 1.0 +/-0.2 mV. 4. Input Terminal DC offset Connect the input terminal to the GROUND and check that the DC voltage Vdc of the output terminal should be 0 +/-75 mV. 5. Gain Test Check that the OUTPUT should be +22.1 +/-0.5 dBu, when a sine wave of 1 kHz at -10 dBu is applied to the INPUT. This test should be performed on PARALLEL operation. 6. Frequency Response Test Filter switch OFF: When a sine wave of 20 Hz, 1 kHz or 20 kHz at -10 dBu is applied to the INPUT, check that the output is 0 +/-0.5 dB at 20 Hz and -0.5 +/-0.5 dB at 20 kHz taking the 1 kHz as a reference. Filter switch SUB WOOFER: When a sine wave of 25 Hz, -10 dBu is applied to the INPUT, check that the output is -3.5 +/-1.0 dB taking the 1 kHz as a reference at the filter switch OFF. When a sine wave of 150 Hz, -10 dBu is applied to the INPUT, check that the output is -3.5 +/-1.0 dB taking the 1 kHz as a reference at the filter switch OFF. Filter switch LOW CUT: When a sine wave of 25 Hz, -10 dBu is applied to the INPUT, check that the output is -4.5 +/-1.0 dB taking the 1 kHz as a reference at the filter switch OFF. When a sine wave of 150 Hz, -10 dBu is applied to the INPUT, check that the output is -3.5 +/-1.0 dB taking the 1 kHz as a reference at the filter switch OFF. INSPECTIONS www. xiaoyu163. com QQ 376315150 9 9 2 8 9 4 2 9 8 TEL 13942296513 9 9 2 8 9 4 2 9 8 0 5 1 5 1 3 6 7 3 Q Q TEL 13942296513 QQ 376315150 892498299 TEL 13942296513 QQ 376315150 892498299 http://www.xiaoyu163.com 14 XS250/350 7. Harmonic Distortion Test When a high quality sine wave is applied at 20 Hz, 1 kHz or 20 kHz, the harmonic distortion should be as follows: *This test should have been finished within 30 minutes. 8. Channel Separation Test 8-1 Apply a -5 dBu, 20kHz sine wave into the channel A. 8-2 Short the input for the channel B with a 600 ohm load. 8-3 Set the output of the channel A at a reference of 0 dB. 8-4 If channel B attenuator is set to the same as channel A, channel B output should be l ess than -65 dB. (RL = 8 ohm) 9. Noise Test 9-1 Set the input attenuator to MAX. 9-2 Short the input with a 600 ohm load. 9-3 Measure at the output, noise level should be less than -65 dBm. 9-4 Set the input attenuator to "∞", noise level should be less than -70 dBu. *Be careful that it is not affected by noise induced during this inspection. 10. Stability Test When a rectangular wave 10 kHz, -10 dBu is applied to the input and a capacitor 10 pF–0.47 µF is connected with 4 ohm load resistor in parallel, the overshoot and the ringing should be as follows. Oversshoot: Vp/Vo