Service manual

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 connector.

Check the AC input connector (4 wire green connector) on the AC mains board

before disconnecting it. Is it tight? If not, seat tightly and reconnect the user

panel following the steps in reverse and try re-applying power to see if the amp

powers up normally.

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 – 3 spots (the breakers, the filter, the 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 turn

ON (visible through the top of the chassis; red leds).

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,