[Drake] R4C S-meter problem

[Andy Bullington]

I just got an older R4C with very gritty sounding audio, especially on CW. I
installed the Sherwood filter caps and power supply board as well as their
little audio board and the radio now sounds fantastic. My only problem
is.....now the S meter doesn't work. It stays over S 9 and doesn't move.
I've checked for continuity and voltage as per the schematic and everything
seems OK. The voltage is 159v instead of 150v but other than that I'm
scratching my head. Any ideas? I've tried adjusting all the pots involved
but no luck. The S meter was working before I did the mods. Thanks!
               Andy W1AWB