yamaha R 900 maintenance tips needed

Hello to all. Just picked up a yamaha R-900 reciever.Befor I put it into service goingto pull a sx-950 or a sherwood S-9910 out of the rec room are there any mods or maintenance issues I should be doing to the yamaha be for I start using it? Any week areas that should be upgraded? Looking forward to your tips, thanks, tom south florida

Power it up without speakers connected and speaker A or B selected on the front panel.See if you get a "click" shortly after power up.