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
Holy Mother of Godzilla! I feel I just graduated from college and earned a Master's Degree after reading Mr. Sean's response! Wow...! A thousand-and-one kudos to Mr. Sean for such an enlightening and thorough dissertation.

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


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.