Ascorbic

I changed out those two 35w caps on the power board today, but it didn't make the slightest bit of difference and I still get the exact same low-level hum.It doesn't really matter as it's not that loud really. I just thought I was on a winning streak, what with dzfan's DIN socket solution

@dzfan, and what great speakers they are. A fix really worth doing, so thanks again for the solution. I just thought to mention that the low-level hum from the sub always annoyed me, so I've been looking into that too. I read a post from 'stpete cooling' here: http://community.klipsch.com/forums/t/129378.aspx He says he services 4.1 systems and he changes out the two 35w caps on the power board (also upgrades them from 85ºC to 105ºC) as a part of every repair as this this stops the hum, particularly in older systems. I'll be doing that tomorrow and if it works out with my 2.1 system I'll add it in the thread.

I just joined the forum to say a H-U-G-E THANK YOU to dzfan... you're a true hero! I'm one of the lucky few with a 230v Promedia 2.1. I bought it about 7 years ago and I've loved it ever since. It cost an arm and a leg with the shipping (I'm in Cyprus), so replacing it, even if a 230v version was still available, is not really an option. My dog decided to park his behind on the DIN plug, which resulted in the exact same problem discussed here. I had no light on the control pod and feint sound from the satellites when the volume was set to minimum, but that disappeared as soon as the volume was turned up. I spent ages searching for a solution, got more and more confused by the strange +/- 14v arrangement in the control pod, then I found this thread. Yesterday I changed out those two resistors (R120/R107) for 1W/82 ohm, but that didn't fix the problem. Then I saw dzfan's post. I removed the I/O sub board that includes the DIN socket as I wanted to clean it up properly. I removed all the heat transfer glue that was holding the sub-board in place and covering the DIN socket -- it actually peels off pretty easily and I think that's much safer than scraping the PCB surface -- then I removed the DIN socket and cleaned up using solder wick. I resoldered the DIN socket pins, reassembled everything, powered up and to my absolute joy everything works again! Words cannot express how happy I am. Thank you everyone for the contribusions you have made to this thread; particularly dzfan for the solution.