Maker Pro
Maker Pro

Stereo problem

E

Eddie

Jan 1, 1970
0
was given a broken sharp 5.1 stereo, they said when you play a CD it
cuts out, and they even tried to get it fixed. They only ever used it
for tuner/CD, and out of those two, CD is the only one that puts out
through the front speakers. I then tried it with some aux inputs that
went through the front speakers and alas my problem was replecated, so
its doing dodgy stuff when using the front speakers. It's behaviour
when it shuts down (blinking timer light) is described in the manual
as speaker shorting/over heating, so last night I open it up to see
any obvious problems, I notice two not very fast fans, when a company
put two fans into a stereo you know its prone to overheating. This
morning I left the covers off, and it's currently playing a CD and
it's up to track 9(as opposed to 30 seconds earlier), so I think its
just overheating.

Any suggestions how to keep it cool? I dont plan on running it with
the sides off, because its dangerous and stupid, at the moment its
sitting on wood on lino just to be safe, so any ideas what I can do?
 
M

Mark D. Zacharias

Jan 1, 1970
0
Could be that one or more speaker wires are indeed shorting together.
Another possibility is bad solder connections.

Many other potential causes. Welcome to the exciting world of electronics
repair.


Mark Z.
 
A

Ampdoc

Jan 1, 1970
0
Sharp usually uses an STK for an audio output. I'd suspect that the STK is
failing when warm. Most common failures in those units are the STK and the
pickup assembly (laser) for the CD. The fans in the unit are actually
connected via a bridge rectifier to the audio output on most sharp units, so
as the output gets louder the fans speed up. If your fans are turning with
the unit at zero volume, I'd suspect some DC bias from the output. They
should not be on at all with no audio out. Some units may differ, but I have
yet to see a Sharp made any other way. A model number would be helpful as I
could look up a manual if it is a US model, however from the original
poster's use of the word "dodgy" I'd suspect he's from the UK.

--
Jammy Harbin
J & J Electronics, Inc.
227 S. 4th St.
Selmer, TN 38375
731-645-3311
 
E

Eddie

Jan 1, 1970
0
Hey Jammy,
I'm actually from Australia, the model is 'cd-dk4500W'
I'm pretty confident it is overheating, with the top off once it
turned itself off, i put a fan next to it and then it worked fine.
any ideas for rectifying the problem? Btw the fans seem to spin fast
all the time, independant of volume
 
T

t.hoehler

Jan 1, 1970
0
any obvious problems, I notice two not very fast fans, when a
companyspeaker channel. You wouldn't want that going into your speakers, you may be
able to see a physical displacement of the cones when the unit is switched
on. I once had a cheapo RCA CD player deck in for repair, it too would run
fine for about 10 - 15 minutes, then started skipping and losing its way. I
opened the unit and it ran fine for a while longer but still crapped out. I
felt the three leg 5 volt regulator stuck in the board, no heat sink, you
could light a cigarette off it. Of course the 5 volts was going south as it
got hotter and hotter. Put a simple aluminum fin on the tab on the package,
all was well after that. Maybe that regulator was out of spec, but it seems
a shame the designers had to cut corners that much to get that cd player out
the door at a cheapo price point. Happens all the time evidently.
regards, and good luck,
Tom
 
Top