I have an older Sony TC-FX4 cassette deck that plays just fine but will
not record/records weakly on the left channel. The VU's show normal
signal coming in during record mode, but when I play back, the left
channel is extremely weak -- barely showing up at all on the left
meter. In fact, you can't even really hear the sound unless you move
the balance to left and crank the volume.

At the same time this problem developed, I also had a problem with
jackhammering/machine gun sound and other interesting noises if I went
directly from record to playback. I tracked that down to the record
relay switch and replaced it which took care of that problem. I was
hoping it had something to do w/ the left channel not recording but I
guess not.

Any help would be appreciated. I don't have a schematic but maybe
someone could point me in the right direction as far as things to look
for that may be causing the problem. Thank you-

Willie