Hello Hasnul, for what you comment, it is very possible that the integrated circuit has been burned, that works with the Front System A output and you have to replace it, the Front System B output, works with another integrated amplifier circuit, which is working well
If you have technical knowledge, I send you the link to download the Service Manual of your Onkio and know which integrated circuit to replace
But, I suggest you look for a specialized technical service
I hope you can solve the problem, comment the results
Greetings Franco Dosil
Hola Hasnul, por lo que comentas, es muy posible que se haya quemado el circuito integrado, que trabaja con la salida Front Sistema A y tengas que reemplazarlo, la salida Front Sistema B, trabaja con otro Circuito integrado amplificador, que esta trabajando bien
Si tienes conocimientos tecnicos, te envio el link para que descargues el Manual de Servicio de tu Onkio y sepas que circuito integrado reemplazar
Sino, te sugiero busques un servicio tecnico especializado
Espero que puedas resolver el problema, comenta los resultados
Saludos Franco Dosil
https://www.vintageshifi.com/repertoire-pdf/pdf/telecharge.php?pdf=Onkyo-HTR-380-Service-Manual.pdf
https://www.intl.onkyo.com/downloads/manuals/pdf/ht-s3300_manual_e.pdf