[ICOM] IC756 Pro III Filters

[Mark K3MSB]

Hello

I've owned my radio for quite a few years (purchased new) and it's worked
without issue.

Recently, I noticed that when I go to the 500 and 250 Hz filter settings on
CW,  the audio is like what you'd hear in the bottom of a barrel.

Prior to this, when switching between the 1.2 Khz,  500, and 250 Hz filter
settings while copying a signal,  the signal was always centered.   Now,
for the 500 and 250 positions I have to adjust the main tuning slightly,
and the signal is not sharp and distinct.

I've performed a reset on the radio which did nothing.

Now, a few weeks ago during an electrical storm I heard a "pop" from the
radio bench.   All antennas were (of course) physically disconnected.   I
forgot to remove the power plug from the outlet strip, but the strip was
turned off.     Afterwards, as is currently the case,  aside from the
filter issue,  the radio works fine.

Any ideas?

Thank you

Mark K3MSB