i hate to ask but I Really Need Help


I recently purchased a plinius 8200 and i am having a serious hum problem, not the kind that is bearable when the music is on, something is not right. To get to the point i am going to list all the facts that may be relevant and what i have done so far.
-i live in the south in a house that is 60 to 80 years old, i do not know anything about the wiring, i rent so any improvements to the system are out of the question.
-i switched the old two prong outlet to a three prong, i connected what appeared to be ground wires but i do not know if the are truly grounded.
-i have tried three sets of interconnects, different speaker cables, using cheater plugs, a RGPC 400, a PS ultimate oulet and different power cords in a number of different combinations to try and solve the problem which i have been sucessful in dealing with in past apartments.
-occasionally when trying different connection combos i have powered on the system and the hum is gone but if i change the volume by touching it sometimes comes back, sometimes it comes back with out being touched.
-HELP! i am completely unable to use my system at this time
i will try to promptly answer any questions that may help
mkaes
Sean,

What a great post! It definitely needs to go in a FAQ on the subject. Thanks.

-Doc
Sean:

My compliments - that is as thorough and helpful a post as I have seen in my 3 plus years on Audiogon. Truly, it is input and helpfulness such as this that will foster a true appreciation for a truly "under-appreciated" hobby/pastime such as ours.

No, I don't have a ground loop problem - I just wanted to commend you on your willingness to help. Nice work!
Sean, You need to get a life, or charge for your services! :-) I'd get carpal tunnel syndrom just from typing one of your typical responses, let alone this one.
LOL...has this now turned into a forum on "Sean" responses...LOL...yet again a plethora of information...I almost feel that there is really no need to post a question in the forum...just email Sean personally...keep up the good work Sean, and invest in a parrafin wax hand bath...I have a feeling it would be a great investment for your audiophile lifestyle...or maybe allthe audiogoners who read your insightful posts should chip in and get you one...I'll send a buck for the cause.

Ellery
I know a lot of homes(older) in the South did not use the regular three wire outlets with neutral, hot and ground. Instead they used the neutral as ground(there is no actual ground wire) I have run into problems actually grounding and/or installing stuff around here. Check the wire and see if it is 2 conductor Romex or if it has a metal shield on the outside going to your outlets. If it has the metal shield, you can use this as a ground.
Try(if you haven't already) rotating the plug 180 degrees on one component at a time and see if the hum will stop. I doubt you have the standard sockets with the large spade small spade opening unless they were upgraded at some point. You can use a cheater plug if need be. You may have a polarity problem with one piece of equipment.
Also, if you have any variable lighting---turn it off. It feeds back on the line in these homes.