I'll be the first to admit I don't know anything about this stuff. Four years ago I got a high end Pioneer Premier deck, new front speakers, an amp, and a sub all installed. Everything worked perfectly for 3 years. At the 3 year mark, my interior speakers would all cut out at once, but the sub would continue to play. About 3 minutes later, the speakers would come back on and play fine for months. This happened more and more frequently, tho, and started to get annoying. I noticed sometimes it was triggered by hitting a bump in the road. Once my speakers went out and I got pissed, so I punched the speaker housing in my door and they came back on. Recently it went out and failed to come back on for a few days. I took it to Circuit City where I had it installed and talked to two different guy, both of whom said it was probably the deck dying. They said if it was one speaker connection failing, then only one speaker would go out and not all the speakers. They said the reason the sub stays on is because it has its own channel output from the deck, which is not having issues. I asked "how come bumps in the road fix/break it?" He said maybe the vibration was causing something in the unit to move into/out of place. I asked "how come when I hit the speaker once that fixed it?" He didn't know. But he told me that they were not wired in parallel, so if only one speaker failed, all of them would NOT go out. He said the reason they're all going out is because the deck itself is failing. He pulled everything out and looked at it, and when he put it back in, nothing would play (not even the sub this time). Questions: did my deck die? I can't help but think the CC guy was being honest because he wasn't trying to sell me any shit in the process. Oh, the CC guy said he could only diagnose the problem if it was happening when he saw it. So on the way there my speakers weren't working, but I hit a bump and they came back on. I was like "oh no he won't be able to see what I'm talking about!" but 2 seconds later they went out and stayed out. Thanks.