回答“buzzing / Noise. Power supply issue?”This issue can also be the EMI filter. This is the actual AC inlet. There are also capacitors and other passive components inside here. If the earth lead from this is also not firmly connected you may get the same buzz shown in this video. Otherwise as others have noted, it is the power supply. You can solve many buzzing issues with reapplication or additonal application of neutral cure silicone or potting compound. You will find quite a bit on there already (those white globs). Just add some more around the transformers, between any larger capacitors that might likely be vibrating against each other. Dont use acidic cure silicone or you will corrode the insides of the machine!