Self-Powered Concert Series
Service Manual
MP-2/4 Amplifier
Doc #: 05.033.040.01
Rev.: A
Date: 08/31/98
Page: 19 of 26
© 1998 Meyer Sound Laboratories, Inc. All rights reserved.
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. 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.
4. With the amplifier sitting on a firm surface, remove the eight (8) small head screws from
the user panel.
5. While slowly removing the user panel, disconnect the audio signal cable from the audio
input board on the user panel by disengaging the locking gray connector. Check the AC
input connector (4 wire green connector) on the AC mains board before disconnecting it.
6. Once the user panel is removed, check the following AC connections:
a). Transformer primary connector (green 7 pin on AC mains board)
b). Transformer secondary connector (green 8 pin on power supply board)
c). AC connections on user panel (breakers, filter, AC inlet).
7. Reconnect the user panel and apply power. Check to see if the following conditions are
met:
a) Audible power-up sequence (three clicks).
Note: This applies to AC supplies ranging from 110-130 V and 225-250 V. For AC supplies
between 90-105 V and 180-215 V, only two clicks will be heard.
b) Center fan(s) turns on.
c) Power supply LED’s on (visible through the top of the chassis)
If the unit still does not power up, unplug the unit and continue to step 8.
8. Remove the user panel and check the AC mains board for damaged components or a
burned electronics smell. Usual mode of failure is a damaged thermistor (the round disc next
to Relay 1). If the AC mains board is damaged, it will have to be replaced.
9. If the AC mains board appears undamaged, remove the Board. To do this, remove the
sense cable (gray ribbon cable) and the transformer primary connector (8 wire green
connector) from the AC mains board.
B. Unit does not power up:
To Next Page
Loading...
Need help?
General
