Audio Systems: Sansui G3000 & Marantz SD221, quiet hum, sansui


Question
I have a Sansui G3000 receiver that has been a real workhorse for me, but of late, it cuts in and out.  If I manipulate the Selector knob, it comes back for a short period.  I'm assuming a short or wear in the knob.  Is it possible to replace that (or is it cost prohibitive), or should I just buy a new receiver (any recommendations, if that's the answer)?  I run everything through it; tape, CD/DVD, TV, and still use the radio as well.
Also, I have a Marantz SD221 cassette player that no longer moves the tape.  It has a quiet hum when on, but I've tried various tapes, to no avail.  Any suggestions on that as well?
Thanks for your time and help

Answer
1) Sansui G3000 - Needs a general overhaul including the cleaning of all of the switches and controls.  This is common and should be no more than $75-$100 in a local shop.  I repair these all the time.

2) Marantz SD221 - This unit needs belts and a good cleaning.  Again this is a common issue.  These are a bit tricky to work on though.  These are solid units and are worth repair.  Try to locate someone that has worked with Marantz equipment.

Dan