Had some hard time finding it, but for everyone's benefit it's available from http://elektrotanya.com/yamaha_rx-v490_r-v701_sm.pdf/download.html
I got one of these RX v490R brought to me by an old friend who bought it in the early 90's. He loved it, but his wife did not and it ended up in storage. Their house is in a village near a chicken farm and the receiver was covered in 1/8" layer of dust and feathers. My friend told me one channel was out.
First thing I did was take it apart - completely to expose all PCB's to an extensive rinse with Iso Propyl Alcohol (IPA). Not going to lie to you. This stuff is expensive so I keep it for my vintage gear. On this Yamaha I used plain Methanol (politure / French Polish thinner a.k.a 'spirt').
Methanol is a more powerful solvent and if you are not careful you will feel a 'sticky' sensation when it starts dissolving the back of the PCB's. This should indicate that it's enough and it's time to wipe it off. Nevertheless, I cleaned the hell out of it until it looked brand new.
The white glue used on the main filter caps and the two smaller ones on the 'effect' board to attach them firm, was smeared all over the place by the manufacturer. Some of it was covering resistors 'legs' and got in between conductors. I de-soldered the caps and dissolved the glue in Methanol. Then completely wiped it off. Those are not really 'big' caps and I don't see why they cannot stay on board with just the soldering holding them in place. I don't think there was a real reason for messing up those board with the white glue material in the first place.
For no reason at all - other than a vintage gear habit - I revived the solder points on R-131, R-132 and R-831 (DC offset related).
Fired the old amp with a variac - went on with no problem! Connected 2, then 4 speakers - just like new. All in all about 4 hours of easy work.
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