"Brian Gaff" wrote in
:

Thanks for replying.

Well, it is most unlikely that both the channels woold go
down together now I'd imagine.

Right.

Firstly, if you do not get a buzz when you touch the live
of these connections, then something is not as expected.
Sharp did tend to do stuff in funny ways though, and as
has been said
elsewhere you need to find out what the turntable actually
did. Was there, for example, as I found on an old Teleton
unit of similar vintage, a little extra cable from the
turntable to the circuit board?

No, there are two (grey and brown, thankfully labeled L and R)
RCA cables which plugged into the bottom of the BSR turntable
where the 4 wires from the cartridge were soldered to the other
side of the 2 RCA connector. I cut them and extended them. And
something went wrong, see below.

This little line appeared
to mute the pick up input in some way, presumably via a
switch on the pick up bearing or similar. I got the
impression it used an optical switch, but as the unit blew
a power amp module shortly afterwards, I never investigated
further..

No, someone else suggested the muting device, but I do not think
this unit had that... It is an amazing piece of vintage quality
TODAY but it was a cheapish thing in its day...

As for 8 track carts, most have seized up by now I'd
imagine as the tape was lubricated. Akai used to make an 8
track recorder which sounded quite good, but the recording
time per track was rubbish and the mechanics were designed
to wear out by the looks of it.

I am curious to see what the deal is here, IF I can find an 8-
track cart. (About 15 yrs ago I knew a guy who had an 8-track of
Lou Reed's "Metal Machine Music" !!!!)

Quite how you cleaned things is hard to see.

I am good at cleaning stuff, and I have a pro circuit board
cleaner. I did not use WD-40 - although I /have/ done so in the
past, with perfect results.

-- Update (very long, I apologize!) --

First of all, many thanks to all who replied. It is very much
appreciated.

Now for the /bad/ part.

Something one person mentioned in his reply made me remember a
rather *crucial* detail which I had forgotten (I am not
completely senile yet, but I have been /incredibly/ busy for the
last few weeks, and my brain is running out of RAM).

It is this: BEFORE I removed the BSR turntable, I DID check to
see whether there was AUDIO SIGNAL coming from it. There was,
loud and clear - when I touched the stylus, it sounded like an
earthquake. Very little "system noise", too.

The turntable itself was "seized" - after I have (with some
violence) managed to take it apart, I saw that the 2 main cog
wheels of the belt-less motor were practically frozen together
at a bizarre angle and would NOT budge. I have NO idea how that
happened - and the 4" screwdriver shaft, 2 children's plastic
letters with magnets, and assorted bits of 30+ year old food I
found inside the receiver could NOT have had anything to do with
it, either, since the BSR motor was fairly well enclosed within
the /incredibly/ complicated mechanical design (a changer).

Now that I have remembered this, it is obvious I screwed
something up. I have never seen a ceramic cartridge, but I am
99.99% positive that BOTH the BSR and the Sony (ca. 1990)
turntable carts are magnetic. So, since I have no signal but
weird pink noise, I must have screwed up the cables. Or do you
think I may have destroyed the preamp?

(This may be a good moment to mention that I am using the term
"phono preamp" in a generic sense. I always thought a phono
preamp might be/would be a small enclosed piece of electronics,
but in this receiver, it appears to be a part of the main
circuit board - the two original (and now extended) cables from
the BSR turntable stylus/arm are soldered right onto the circuit
board, and go who-knows-where - presumably, into components
which make up this receiver's "phone preamp" section.)

(THIS may /also/ be a good moment to mention that while I have
had some disastrous luck with simple things and astoundingly
good luck with complicated things, I am NOT a technician, and do
not own an oscilloscope - I check connections with two gator
clips connected to a 1.5V battery with a flashlight bulb, and
after over 30 years of "considering it", I finally bought a five
dollar "voltmeter" which /appears/ to work - I found out a cheap
110V/22V AC/DC adapter outputs 25VDC when set to 12V output
[when the input voltage is set to 110V] and 12.5VDC from its 9V
setting [when the input voltage is set to 110V (it is 110V
here)]. The Sony turntable (originally a component of a system,
with a tiny power connector which plugs into the back of the
main system unit and where I found out 12VDC is output) is
running on a supposedly "regulated" fancy Radio Shack AC/DC
adapter which puts out 11.8V DC. (When I reverse the polarity,
the turntable spins backwards.)

If anyone has read this far, please accept my deep thanks for
your patience. I can't write more concisely - I realize it's an
illness.

Anyway - the question now is WHAT did I do to mess things up?
Since I consider the receiver largely indestructible, I do not
think I have *destroyed* anything, not to mention the voltages
involved are totally minuscule and it being a solid state unit -
as the front panel proudly states ;-) - there is little danger
of blowing it up. Plus everything else works.

My plan is as follows:

1. Cut the original "BSR cartridge/turntable to the main circuit
board" cables, strip ends.
2. Attach gator clips to them and connect to the Sony turntable
output cable.
3. Hopefully, hear sound. Extend cables again, making SURE I
don't screw up this time.

If I hear no sound, I will connect the 4 very thin cables from
the original BSR cartridge (I saved the cart assembly and cables
before I saw the turntable was connected to the circuit board
with 2 standard cables with RCA plugs) to the cut cables leading
to the circuit board and see if I hear anything. If I do, I will
post for more advice.

But for now, my question is:

If after doing all this, I still get the /same/ pink noise (NOT
hum - strange, huh?) and get NO audio, WHAT do I do?

Thank you /very much/ for your patience, and my apologies for
having forgotten a crucial part of the puzzle. Further help will
be greatly appreciated. If anyone wants to see pix of the 2
cartridges or the circuit board where the phono audio cables are
soldered into it, I can post them to photobucket or something,
OR a binary group if you have binaries access.

The replies are different in every one of the 5 groups, so I
will post this followup to each group separately. I don't really
understand how crossposting works, since I never do it, and
eternal september /may/ be "funny" about crossposting to boot.


--
Any mental activity is easy if it need not be subjected to
reality.