"reglarnavy" wrote in message
oups.com...
I've got a Sharp CD BA300 stereo/CD system that's now hung up in
"Protection" mode. That's what the display says, and of course, it
doesn't do anything. Pretty sure something's blown out in it ...
output IC's? Haven't had the chance to open it up yet, but hope to get
to it soon. Bruce


Assuming that you haven't got a shorted speaker cable, or a bad speaker, the
most likely cause is a blown output IC, particularly if there is a short
delay between coming out of standby, and the message appearing. "PROTECTION"
on audio amplifiers, usually indicates that the output relay is deactivated,
to either protect the output stages from an excess load - a shorted speaker
or cable for instance - or to protect the speakers from DC, which would
otherwise be appearing at the output connectors from a blown output
transistor in the output chip. There are other possibilities. Sometimes, the
protect circuitry itself fails, and sometimes it monitors supply rails as
well. In this case, something as simple as a fuse ( although it may not look
like any fuse you would recognise ) can cause the message to appear. Most
likely bet from experience though, is the output IC.

Arfa