Amplifier Hum

I have an Aragon 4004 MKII which is emitting a humming noise from the amp itself. The noise is there regardless of volume, and it is not transmitted through the speakers. Someone told me that it may be transformer that needs to be replaced.

Does anyone here know if this is the problem? If it is, what does that entail -- i.e. shipping it to Aragon? Can this be fixed locally, or by myself? Should I not even worry about this problem?