i have a sony str de335 digital stereo/home theater receiver that my friend let me borrow but i noticed that the right speaker output didnt work no matter what i tried. since lately ive been taking apart (and actually successfully repairing) my old broken electronic equipment (a yamaha keyboard with synthesizer, my vintage jvc receiver, and a guitar modeling processor pedal), i figured i would do him a favor and try and fix it. so i took it apart and cleaned out all the dust and gunk. but now when i put it together there is now absolutely no sound that comes through the speaker out puts. not the left or right, not the rear or center. i cant even get sound when connecting headphones to the headphone jack in front. ive thoroughly inspected practically ever inch of it to see if there was anything visible.....there doesnt seem to be. and now i feel bad and am considering taking it to be repaired (even though the person from the stereo repair place said it would probably be more trouble and money than its worth). im just wondering if there is anything i can do at home (ordering a new part/circuit) for cheap. i have an expansive collection of tools so im not at all worried about that. i just need to know how i can find the problem. and i know i reconnected everything correctly (there wasnt anything inside that i couldnt even have put in the wrong place), but i can acknowledge that aside from basic understanding of electronics and well-rounded common sense, i virtually know nothing about repairing things like this so any help or information would be greatly appreciated!!! thanks!!