Service manual

13. Return the unit to the upright position and disconnect the audio signal ribbon

cable from the bottom control board by unlocking the connector.

14. Remove the green four (4) pin male connector mounted on the top edge of

the amplifier chassis; this leads to the bottom amp heatsink assembly.

Note: Two (2) nuts with lock washers secure the two (2) screws. Make sure to

remove these nuts from the chassis.

15. Lift up the bottom amp heatsink module in order to remove the white DC

power harness from the connector on the amp heatsink module. Disconnect the

power harness from the amp heatsink module.

Note: As you are lifting the amp heatsink module, thread the white DC power

harness through the chassis towards the amp heatsink module. This will allow

you to lift the module clear of the amp chassis.

16. Remove the bottom amp heatsink module, taking care to not disturb the

position of the fans. Do not remove the control board from the amp heatsink

module at this time.

17. Position the AC Mains board inside the chassis and replace the three (3)

screws into the top of the chassis to reattach the AC Mains board bracket.

18. Connect the sense cable and the transformer primary cable. Also replace the

user panel.

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.

For AC supplies between 90-105 V and 180-215 V, only two clicks will be

heard.

b) Top and bottom center fans turn on.

c) Power supply LED’s on (visible through the top of the chassis)

Note: The user panel LED will not light as the amp heatsink module is

disconnected.

20. If the previous three conditions are met, the power supply circuits are

probably functioning properly. It is most likely that one or both of the amp

heatsink modules are damaged and will need to be replaced.

You can install the bottom amp heatsink assembly and apply power to the unit if

the three previous conditions are meet the top amp heatsink module is the likely