Fault
Amplifier in protection mode power LED Amber.
Dry solder joints on the pins of the output Mosfets.(IRF540N)
Connections re-flowed fixing the protection mode issue.
Dry solder joints on the following also re-flowed.
Input RCA sockets.
Speaker Terminals
Power Socket
Headphones socket
Bass, Treble, Balance 7 volume controls.
Selection switches Tape, Direct and SP2.
Input selection switch removed and taken apart.
Wafer contacts cleaned with a fibre glass pencil to remove oxidization.
https://uk.rs-online.com/web/p/abrasive-pencils/1835226
Switch re-assembled and fitted.
Speaker protection relay as shown in the video replaced to avoid any issue with intermittent sound loss or distortion at low volume.
User controls cleaned with De-Oxit to ensure noise free operation.
Bias for each channel set to 3.2 millivolts.
Service Manual https://www.hifiengine.com/manual_library/arcam/alpha-7.shtml
Amplifier fully tested working correctly.
Amplifier in protection mode power LED Amber.
Dry solder joints on the pins of the output Mosfets.(IRF540N)
Connections re-flowed fixing the protection mode issue.
Dry solder joints on the following also re-flowed.
Input RCA sockets.
Speaker Terminals
Power Socket
Headphones socket
Bass, Treble, Balance 7 volume controls.
Selection switches Tape, Direct and SP2.
Input selection switch removed and taken apart.
Wafer contacts cleaned with a fibre glass pencil to remove oxidization.
https://uk.rs-online.com/web/p/abrasive-pencils/1835226
Switch re-assembled and fitted.
Speaker protection relay as shown in the video replaced to avoid any issue with intermittent sound loss or distortion at low volume.
User controls cleaned with De-Oxit to ensure noise free operation.
Bias for each channel set to 3.2 millivolts.
Service Manual https://www.hifiengine.com/manual_library/arcam/alpha-7.shtml
Amplifier fully tested working correctly.
- Category
- Audio
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