I have finally managed to talk my tech into having a go at my CS 50 -- any things that require particular attention or that should be looked at? My 50 has the habit of occasionally producing portamento on some notes even though no portamento has been dialled in. Sometimes (very rarely) notes with a long release have a tendency to drift upwards in pitch -- I seem to remember that this is due to some caps gone bad on the KAS board, is that true? What CMOS components should be replaced as well?