C4 Bose Amp Fix

First, let me qualify
this post: This fix is for most BOSE amp boards in C4 Corvettes. If your
amp board doesn’t look similar to the one shown below, yer
outta luck.
From my experience (and that of others) I give
this fix a 70% success
rating.

I CAN’T POSSIBLY
GUARANTEE
THIS WILL FIX ALL BOARDS, but if it’s between
spending $85 and $150 to
replace a board, I suggest you try
this fix first. I fixed two of my Bose
amp cards by replacing
two capacitors on each board ($1.00 for each capacitor)=total
cost $4.00 total time = 4hours, from removal to re-install two
speakers/amps).

If you don’t have
any
experience with soldering small printed circuit boards I STRONGLY
SUGGEST YOU FIND A FRIEND THAT HAS DONE CIRCUIT BOARD SOLDERING. It will
take you, or your friend, about 15 minutes per card to do the
”electronics”
part of this job. Your local stereo repair
shop will probably charge you
$20-$60 for the repair but I
doubt you’ll get any guarantees from him
either!

I suggest you (or
your soldering friend) first
look over the board for any signs of burnt
parts. If you think
you found something that looks burned…smell it.
That’s
right, sniff the area near the suspected burn. If it smells
burned…you’re
probably outta luck UNLESS the burn is in
the area of the two capacitors
(they may have physically
popped).

Go to Radio Shack,
or your fav.
electronics parts shop, and buy two (Hell, get three in case
somebody messes one up) of the following parts for EACH board: #272-958
(1000uF, 16 WVDC, Electrolytic Capacitor, radial leads). Yes,
I know the
caps that are in the stock boards are 860uF but
they’re difficult to find
and the 1000uF’s will work
fine. Friends will always be faster at helping
if you supply
the parts!

The top of the board
has most of
the components (smt parts are on foil side). See the two circled
small cans on the picture below? These are probably the offending
capacitors,
the ones you’ll be replacing.

You’ll notice there’s
rubbery
”goop” on the inductors (coils of wire) that has probably flowed
onto the caps. Carefully cut it away with an exacto knife. You don’t
have
to remove all of it! Just enough to free the cap after
it’s been unsoldered.

Next go to the bottom
of
the board and look for where the the cap wires are soldered to the
board. They’re in the rectangles in the pic below.

CAREFULLY apply heat
to the solder
pads of the caps while simultaneously pulling the cap away
from the component side of the board. After you’ve removed the caps you
gotta get the new one’s in. (Too much heat will lift the
solder pad, but
soldering folks should already know this).

If you’ve got a solder
sucker, solder wick or
soldapullit, remove the solder from the holes insert
the caps
(watch for the polarity, the – signs must be towards the edge
of the board) and use A VERY TINY AMOUNT of solder (rosin core of course)
to complete the job. If you don’t have any of the above
tools (like me)
you’ll have to try clearing out the holes
or try pushing the cap leads
through while heating up the
solder pads.

Make sure your ignition
and radio
are both turned off when you plug the amps back in. Then test
the system BEFORE re-mounting and screwing everything back in place!

It may sound like
a bitch, but you know what they
say about having the right tools for the
job. I’ll be back
to check and see if I can offer additional help.

Good Luck!