This Bose CD-3000 tabletop player was brought to my attention because
intermittently there were popping/static noise was coming out of the
speakers. It was quite loud. When I powered it up via the 12 volts input,
the problem didn't seem so noticeable. I took it to the shop, opened it up,
and noticed there were two car stereo-type speaker amplifier chips powering
the speakers. Using these two datasheets,
http://www.datasheetcatalog.org/data...onics/1512.pdf and
http://pdf1.alldatasheet.com/datashe...S/TDA7375.html I
was able to figure out that the TDA7375 powers the left and right speaker
and the TDA7396 powers the subwoofer. I checked the prices of replacing
these parts and each one was less than $10. Since the pc board where they
resided was difficult to access and make tests while powered on, I decided
to replace the stereo amp chip. It didn't help. I figured then it had to be
the other chip. I replaced the other chip with no improvement. Then I
figured out a way to remove all the pc boards and cables and power it up
outside the unit where I could make some meaningful tests. First of all,
there was some small dc offset going to the subwoofer. I soldered a 330 ohm
0.5 watt resistor across the subwoofer output terminal so it would have some
load. It was about 340mv. Not great but certainly passable. Then after about
15 seconds, the dc shot up to 12 volts and my bench meter showed a spike in
current. This voltage swing delay occurs every time I power it on. If I just
disconnect the subwoofer, the left and right speaker outputs are fine. A
schematic would be of immense help here or perhaps someone has had some
experience with this unit. Any and all suggestions are welcome.

Thanks for your reply.
--
David Farber
Los Osos, CA