NAD C315BEE Amplifier Repair

Описание

Fault
Amplifier not powering on.

Initial inspection confirmed that the input power protection fuse
F41 T1.6 Amps had blown as shown in the video.

The fuse was replaced and the plug connector for the secondary of the transformer disconnected.

The Amplifier was then powered up via the Dim bulb tester which glowed very bright confirming shorted turns on the primary of the power transformer.

Replacement Transformer fitted specifications are shown in the video.

Before the secondary of the transformer was reconnected additional work was completed.

The two large power supply smoothing capacitors always dry out over time resulting in 100Hz power hum.

Often the capacitors will be bulging on the top or brown liquid may be seen around the base of the caps, they will also rattle if shaken confirming they have completely dried out.

C3224 and C323 10000 uf 50 Volt replaced.

The video also shows brown glue around a number of other electrolytic capacitors, to avoid any future issues with corrosion and conductivity the glue was removed.

The solder side of the board was checked for any dry or suspect solder joints, a number were reflowed.

The bias for each cannel was set to 7 millivolts as detailed in the service manual.

Amplifier fully tested working correctly.