yamaha psr76 keyboard sound goog but low and no phones/aux

[frank]

Hi; guys i got this Yamaha keybord that i found in the trush,it has good sound in both speakers but the only drawback is that the sound is very low dispite the volume is in the max.and no phones/aux output at all
no faut like hum nothing just too low,it has a power amp ic LA4598 which is discontinued. checked all ellectrolitics with a ESR tester all fine any ideas thanks in advance.

[vtech]

LA4598 is a discontinued product but is still available.
dload it's data sheet & use it as a reference to monitor the signal/voltages--at least you can verify it is not the output section. If you know the basics of signal tracing, it should not be difficult to pinpoint where the signal is getting lost & or muted, provided you have a scope.

[Guest]