Mitsubishi VCR Audio Problem
 

I have a Mitsubishi HS-MS11V VCR, which is a multi system Hi-Fi VCR,
the tuner of the VCR works fine on tuning different channels and the
screen looks just fine, but it generates high pitch feedback noise
from both audio outs, it just sounded like a 2-3 kHz tone, if I unplug
the antenna or switch the input to L1 or L2, the feedback noise gone,
anyhow, it plays fine on any recorded videotapes, both the screen and
sound, could anybody know what's up with it.