Allnic H-3000 hum when mute button engaged.


Hello Goner,
I have just purchased this wonderful phono preamp used. The unit is running perfectly and quietly. There is only one problem, that is when the mute button is engaged, my speakers hum badly on bith sides. Anyone got any idea on what happens. Also, when the button engaged and disengaged, it produce the pop sound. Is it the possibility that the mute button is malfunctioning? Can a simple deoxit fix it?
 Thanks 
Calvin
dangcaonguyen
Hi Lewm,
Here are the list of my components:
 Garrard 301 with 2 tonearms:
Moerch  DP-6 with ZYX Aries 3 Moerch  Phono Cable
Polstar PS-UNV2 with ZYX Omega Gold, Polstar phono cable
Allnic H-3000
Homemade Silver IC
Shindo Aurieges
Shindo Interconnect
Shindo Montille EL84
Belden Speaker Cables
Devore Fidelity The Nines

I dont have any balance IC to try for now.
I will switch my homemade IC to the MIT avt1 IC to check.
 Thanks for the suggestion.
Calvin
@whart and @lak 
Thanks for your suggestions. I will contact Albert, but for now i am still waiting for the answer from the seller before moving forward on what to do with the unit. It is strange, I have emailed him for 2 days without answer. He might not checking emails over weekend.
Calvin
Calvin, Do you live on the East Coast, USA?  If so, I can strongly recommend Bill Thalmann in Springfield, VA. Bill is a fine person and smart repair guy who is completely honest.
Forgot to note that your Shindo stuff is strictly single-ended.  So I don't know whether you can really do true balanced mode, to test the function of the switch.  (I am not even sure how the Allnic achieves balanced output.  It might be via a transformer, since I would bet the circuitry is actually SE.)