Self-Powered Concert Series Service Manual Doc #: Rev.: Date: Page: 05.033.040.01 A 08/31/98 1 of 26 MP-2/4 Amplifier Self-Powered Concert Series MP-2/4 Amplifier Service Manual © 1998 Meyer Sound Laboratories, Inc. All rights reserved.
Self-Powered Concert Series Service Manual Doc #: Rev.: Date: Page: 05.033.040.01 A 08/31/98 2 of 26 MP-2/4 Amplifier TABLE OF CONTENTS INTRODUCTION 3 SECTION I: MP-2/4 AMPLIFIER SYSTEM DESCRIPTION A) MP-2 Exploded view diagram and parts list B) MP-4 Exploded view diagram and parts list C) System block diagram. D) Explanation of system block diagram.
Self-Powered Concert Series Service Manual Doc #: Rev.: Date: Page: 05.033.040.01 A 08/31/98 3 of 26 MP-2/4 Amplifier Introduction: From the very beginning, the Meyer Sound Self-Powered Concert Series products were designed with the customer in mind. Not only are they easy to set up and use, but they are also easy to service. You will find that the MP-2 and MP-4 Amplifiers used in the Self-Powered Concert Series are completely modular.
Self-Powered Concert Series Service Manual Doc #: Rev.: Date: Page: 05.033.040.01 A 08/31/98 4 of 26 MP-2/4 Amplifier Pre-Service Checks and Precautions: 1. When servicing any electronic assemblies, a clean low static bench should be used and internal assemblies should be kept free of metallic debris. 2. AC power must be disconnected and the Power Supply module allowed to bleed for at least 3 minutes before performing any work inside the chassis. 3.
Self-Powered Concert Series Service Manual Doc #: Rev.: Date: Page: 05.033.040.01 A 08/31/98 5 of 26 MP-2/4 Amplifier I. MP-2/4 Amplifier System Description: A) MP-2 Exploded View Diagram The illustration below shows how all of the individual modules for the MP-2 amplifiers interconnect. Please note that some modules are used in MP-4 amplifiers as well. For current pricing please reference to the Meyer Sound Price List. MP-2 TPL Control Board 40.033.042.01 MSL-4 40.033.042.04 PSW-4 40.033.042.
Self-Powered Concert Series Service Manual Doc #: Rev.: Date: Page: 05.033.040.01 A 08/31/98 6 of 26 MP-2/4 Amplifier B) MP-4 Exploded View Diagram The illustration below shows how all of the individual modules for the MP-4 amplifiers interconnect. Please note that some modules are used in MP-2 amplifiers as well. For current pricing please reference to the Meyer Sound Price List. MP-4 Amplifier/Heatsink Module Top and Bottom 40.033.013.02 MP-4 TPL Control Board 40.033.042.02 MTS-4 Bottom 40.033.042.
Self-Powered Concert Series Service Manual Doc #: Rev.: Date: Page: 05.033.040.01 A 08/31/98 9 of 26 MP-2/4 Amplifier D) Block Diagram Description: 1) (Rear) User Panel: The user panel block is divided into two main sections: AC Power and Audio Signal Path. The AC power is applied to the system via a L6-20 twist-lock connector or an IEC 309 connector. The line voltage is fed thru an RF filter and then connected to circuit breakers. For 115 V applications, both circuit breakers are used.
Self-Powered Concert Series Service Manual Doc #: Rev.: Date: Page: 05.033.040.01 A 08/31/98 10 of 26 MP-2/4 Amplifier The 10-pin ribbon cable from the XLR board widens to 16 wires where it interfaces with the Communications module which then continues to the TPL Control Board. The extra 6 lines feed signals, such as output voltage and power, from the Amplifier/Heatsink module and the TPL Control board to the Communications module.
Self-Powered Concert Series Service Manual Doc #: Rev.: Date: Page: 05.033.040.01 A 08/31/98 11 of 26 MP-2/4 Amplifier 5) Power Supply Module: The power supply provides the Amplifier/Heatsink module with ± 120 V DC and ± 45 V DC, which is used for the Power MOSFET rails. This module also supplies ± 15 V DC to the Amplifier/Heatsink module and the TPL Control Board for powering op-amps.
Doc #: Rev.: Date: Page: Self-Powered Concert Series Service Manual 05.033.040.01 A 08/31/98 12 of 26 MP-2/4 Amplifier II.
Self-Powered Concert Series Service Manual Doc #: Rev.: Date: Page: 05.033.040.01 A 08/31/98 13 of 26 MP-2/4 Amplifier III. Common Failure Modes: A. Circuit breakers trip on power-up or during use: 2-Channel Versions 1. Do not reset the circuit breakers. If the circuit breakers are reset without first determining the cause, further damage to the electronics may result.
Self-Powered Concert Series Service Manual Doc #: Rev.: Date: Page: 05.033.040.01 A 08/31/98 14 of 26 MP-2/4 Amplifier If any of the previous three conditions (step 8) are not met, continue to step 11. Note: If you are going to replace the Amp/heatsink module, make sure that the AC Mains board is in good condition and not stressed, checking the thermistor for cracks or visible burns. If the thermistor is damaged the AC Mains module should also be replaced.
Self-Powered Concert Series Service Manual Doc #: Rev.: Date: Page: 05.033.040.01 A 08/31/98 15 of 26 MP-2/4 Amplifier 14. While firmly holding the AC mains board, remove the three (3) screws on the top of the chassis and remove the entire board. 15. Replace the AC mains board with a known good board (either new or from another unit). Make sure to reconnect the sense cable and the transformer primary connector. Replace the user panel and repeat the power up sequence as stated in step 8. 16.
Self-Powered Concert Series Service Manual Doc #: Rev.: Date: Page: 05.033.040.01 A 08/31/98 16 of 26 MP-2/4 Amplifier 7. Remove the eight (8) small head screws from the user panel. 8. While slowly removing the user panel, disconnect the audio signal cable from the input board on the user panel by disengaging the locking gray connector. Also disconnect the AC input connector (4 wire green connector) from the AC mains board. 9.
Self-Powered Concert Series Service Manual Doc #: Rev.: Date: Page: 05.033.040.01 A 08/31/98 17 of 26 MP-2/4 Amplifier 19. At this point the top and bottom amp/heatsink are disconnected but the AC mains board is in place and connected. Reset the breakers, and apply AC power to the power supply. Verify the following conditions: a) Audible power-up sequence (three clicks). Note: This applies to AC supplies ranging from 110-130 V and 225-250 V.
Self-Powered Concert Series Service Manual Doc #: Rev.: Date: Page: 05.033.040.01 A 08/31/98 18 of 26 MP-2/4 Amplifier f) If one of the Amp/heatsink modules is found to be good, replace its Control board, and install the Amp/heatsink module into the chassis. Caution: Connect the brown DC harness to the module as the white DC harness is currently disconnected When plugging the large brown DC power connector into the amp board. Make sure the connector is not shifted over one pin to the left or right.
Self-Powered Concert Series Service Manual Doc #: Rev.: Date: Page: 05.033.040.01 A 08/31/98 19 of 26 MP-2/4 Amplifier B. Unit does not power up: 1. Using a voltmeter, check the AC voltage supply to the amplifier. Make sure that the voltage is within the specified operating range as listed on the user panel. Note: If the AC voltage exceeds 270 VAC, the AC mains board may be damaged. 2. Verify that the breakers are not tripped. If the breakers are tripped, do not reset. See section A for details. 3.
Self-Powered Concert Series Service Manual Doc #: Rev.: Date: Page: 05.033.040.01 A 08/31/98 20 of 26 MP-2/4 Amplifier 10. While firmly holding the AC mains board, remove the three (3) screws on the top of the chassis and remove the board. 11. If the unit was subjected to overvoltage conditions (> 270 VAC), the AC mains board fuse could be damaged. Locate the fuse (F1) on the AC mains board (between Relay 1 and the AC input connector) and check the continuity with an ohmmeter.
Self-Powered Concert Series Service Manual Doc #: Rev.: Date: Page: 05.033.040.01 A 08/31/98 21 of 26 MP-2/4 Amplifier D. Unit powers up but does not unmute (pass signal): 1. If the amplifier is in the speaker cabinet, remove the eight (8) large head screws that attach the amplifier to the cabinet. As you slowly remove the amplifier from the cabinet, look at the green speaker connector(s) on the top of the amp chassis. Make sure that the connector(s) is fully seated.
Self-Powered Concert Series Service Manual Doc #: Rev.: Date: Page: 05.033.040.01 A 08/31/98 22 of 26 MP-2/4 Amplifier E. Unit powers up but Active LED does not light and signal does not pass: 1. If the amplifier is in the speaker cabinet, remove the eight (8) large head screws that attach the amplifier to the cabinet. Remove the amplifier from the cabinet slowly, taking care to unplug the green speaker connector(s) on the top side of the amplifier. 2.
Self-Powered Concert Series Service Manual Doc #: Rev.: Date: Page: 05.033.040.01 A 08/31/98 23 of 26 MP-2/4 Amplifier F. Unit turns on and off in a cyclical fashion: 1. Check the AC line for fluctuation or sag under load. This can be best achieved by using a "Y" connector on your power cable. Connect one side of the "Y" to the amplifier and the other side of the "Y" to a voltmeter. Monitor the voltage as the unit turns on and during use. 2.
Self-Powered Concert Series Service Manual Doc #: Rev.: Date: Page: 05.033.040.01 A 08/31/98 24 of 26 MP-2/4 Amplifier If broken solder joints or burned resistors are found, the Audio Input board will need to be replaced. Note: Ground loops carrying high voltages can burn some resistors and traces in the Audio Input board.
Self-Powered Concert Series Service Manual Doc #: Rev.: Date: Page: 05.033.040.01 A 08/31/98 25 of 26 MP-2/4 Amplifier If broken solder joints or burned resistors are found, the Audio Input board will need to be replaced. Note: Ground loops carrying high voltages can burn some resistors and traces in the Audio Input board.
Self-Powered Concert Series Service Manual Doc #: Rev.: Date: Page: 05.033.040.01 A 08/31/98 26 of 26 MP-2/4 Amplifier J. Unit has distorted output: 1. Try running the same signal (individually, not looped) into two similar units. If both units are distorted, check the signal source level for overload. 2. If only one unit has distorted output, perform driver evaluations. Refer to Driver Inspection and Evaluation Procedure for Self Powered Series Products ( Low Driver #17.010.120.01 and High driver #17.
