Alpine Head Unit Frying RCA Cables?

I have a 1997 Honda Accord and figured I'd toss this question at you fine
people. I know many of you have helped me in the past.

I have quite an odd problem. My friend and I have troubleshooted it and have
found the problem must be caused by the Alpine head unit.

I have an Alpine head unit, a Kohl Audio amp, and two Alpine Type-E subs. The
system has worked fine for a few months. Recently, we noticed one sub is
working fine while the other is extremely low. We looked at the amp, which is
fine and found the RCA cable was the problem. We could change the sub not
working properly by switching the RCA cables in the amp.

We replaced the RCA cable with a new one and all was well. A few days later,
the problem reoccured. Once again, the wire is not working. One part of the RCA
works fine, while the other does not. The problem can again be switched to the
opposite sub by changing the wire in the amp.

As such, we figure the head unit must be frying the RCA cable somehow. I spoke
to Alpine and I need to send the head unit back (with me paying shipping) to
have them look at it. If that isn't the problem, I pay all costs. Otherwise,
they cover it.

It's a major pain in the butt, but regardless, I'm upset this problem has
reoccurred. Has anyone heard of this problem or know of an alternate solution?

Any help would be appreciated! Thanks in advance.

- Brian

 

If that one amp is not properly grounded, you could have a situation the
ground current flows through the shield of the RCA cable and back to the
head unit and finds ground there. Current in the ground lead is equal to
the current in the positive supply lead for the amp, and the RCA cable
is not designed to handle that kind of currents.

 

If the fault is cleared by replacing the RCA cable, there must be some
evidence as to what happened to the cable. Think of it as a two core
cable. The possible fault could be the inner core going open circuit
OR the inner core shorting to the outer core. So measure the cable's
continuity to see what its problem is.

It is possible that some other action has dameged it. If it is behind
the dashboard perhaps a heater/AC lever has mangled it and
broken a core, etc..

 

After some more testing, we found it was the left output of the head unit where
the problem stemmed from. For some reason, replacing the RCA cable solved the
problem the first time, but not the second.

Back to Alpine the head unit goes.

Thanks for the help.

- Brian

 

Sounds like a cold solder joint to the RCA connector on the head unit.
When you plugged in the new cable, you jammed it back in contact for a
while.

--Gene