Audio Systems: Intermittant Loss of Drivers side volume, mechanical vibration, channel amp

Question
Hi, again, Tom, and thanks so much for the prompt reply. I have one general question that came to mind when I read your response to my initial question: Do these "defective connections" typically come from faults in the cables and adapters used to connect the cables to the components (ie, amp, head unit, etc) or does the problem more commonly stem from a fault instrinic to the component itself, requiring replacement of that component?-------------------------
Followup To
Question -
Hello, Tom. I have an aftermarket system consisting of a Nakamichi head unit, Zapco equalizer, Helix 5 channel amp and subwoofer and, of course, front and back speakers.  Intermittantly, and not clearly connected to mechanical vibration from bumps in the road, the power to the front and back speakers on the driver's side is mostly, but not completely, lost. This can last a few hours or more, and then--seemingly at random--full power returns and stays there for hours or days, till it cyles again.  Where in the circuit may the fault lie? and what type of fault might this be? I took it into the guy who installed it (who I fear is not very motivated to fix something one year after the initial install, although he is obligated to do so) and he "tightened some connections" and "thought that that fixed it".  It did help (whatever he did) for a few weeks, but it just recently started happening again. Any hypotheses would be appreciated, so I can pass them along to the not-so-motivated installer.  thank you so much,
Dan Fisher
Answer -
Hello Dan,
It sounds like some kind of defective connection is at hand. It may be in the left channel of the head unit itself. A little trick that you can try to pinpoint the problem is as follows. Install a y-connector in the left channel input to the amp and using adapters connect up a cheap set of head phones. When the sounds goes low you can listen to the head phones to see if the sound level is the same as when it was working OK. if it is then you should move the y-adapter closer to the stereo to use the process of elimanation to locate the fault. Another test that you can try that I almost always use to locate defective connections, is to lightly tap on the seperate units until you locate the unit that when tapped on will make the sound go off for one or both channels. You may want to start with the EQ unit first because this is where I find many of the defective connections before any thing else.

TOM,
T&D ELECTRONICS
tdeser@zoominternet.net

Answer
Dan,
Most of the time I find the defective connections on the RCA input/output jacks on the circuit board of the eq units. When you mentioned about the sound, does the sound go completely off or does it drop drow to a very low level that you can still hear? when the sound drops, this would be a good time to do the tap test as long as you are parked!


TOM,
T&D ELECTRONICS
tdeser@zoominternet.net