TRIO TS-120S repair

TX was NG,I checked any test point,then I found out AVB voltage was low.
I exchanged Q9(2SA473) on filter unit

so,TS-120S resumes norma operation.l

maybe TS-120S has a weak point at Q9 on filter unit.
because some people said that when TX was NG and AVB was low,you need check Q9 on filter unit.
thank-you.