The DSBG is on the front vertically mounted power circuit board where you can't easily spot the issue. You should also have the .22uf X2 cap on the Control 1 power supply board looked after.
I'm still trying to decide if the M-70 or M-80 has the worst binding posts ever... It's a shame as they are all such nice sounding amps.
( DSBG) Damn SONY Bond Glue. A lot of japanese manufactures and others. Used a glue to fasten down larger components such as heatsinks and large capacitors. By now the glue is all or mostly crusty dark brown/black. It attracts and retains moisture. If it is in contact with jumper wires or component leads it will eventually oxidize the leads/jumpers to the point of failure.Best to eradicate the stuff...What do you make of the statement of Sony adhesive failure? What exactly is this referring to?
( DSBG) Damn SONY Bond Glue. A lot of japanese manufactures and others. Used a glue to fasten down larger components such as heatsinks and large capacitors. By now the glue is all or mostly crusty dark brown/black. It attracts and retains moisture. If it is in contact with jumper wires or component leads it will eventually oxidize the leads/jumpers to the point of failure.Best to eradicate the stuff...
No it is not heatsink compound...
May be a good idea to research the benefit of using higher uF caps in a power supply, Mundorf absolute quality and the high end parts supplier of Parts Connexion.I would prefere parts avalible at mouser, if anyone can send a link for suitable 10000µF and 18000µF replacement i would be greatfull.