Arfa Daily wrote:


OK on that Tim. The record / playback switch is not usually located on the
deck itself. It is normally a slide-type multipole switch, actuated by a rod
or lever or stiff wire, from the deck.
Whether or not the deck is directly controlled or servo controlled by logic,
is not normally an issue, with regard to this mechanical scheme.

Some cassette machines, however, do employ full electronic switching, which
is sometimes part of the record / playback subsystem IC. If this is the case
with your machine, then you will probably not get much further without a set
of schematics, and a 'scope. Have you tried to see if it records
successfully on both channels ? If it does, that at least for the most part,
proves out the heads and their wiring. It's pretty unlikely, but I'm
assuming that you have not got a very badly clogged head ? Normally, you can
still hear something on the affected channel, when playing back a previously
known good tape, but just occasionally, you can get a case that's so bad,
that you get nothing at all.

Arfa



Ok I had a good look over it again today and I'm pretty sure that this
deck does not have a mechanical record/playback switch. The only
switches on the board are those for selecting the tape type and Dolby
NR. It would seem that it is done electronically although there are
very few ICs on the board - mostly discrete components. As it happens I
do have a scope that I acquired for free but I don't think I have much
chance of obtaining schematics as it is a fairly old unit - appears to
be made around 1983 going by the dates marked on the motors.

Just to check the head for sure I tried reversing the connector that
goes to the board since it is wired symmetrically. Sure enough I got
the same result - playback only on the left channel, although this time
the signal being supplied from the right output of the head. This seems
to confirm that the head is good and unfortunately it's an electronics
fault. However, I did try a test recording and it records on the left
channel only. I checked by playing back on a known good tape deck. If
I turned up the volume on my hifi amp much higher than normal listening
level with the balance control all the way to the right I was able to
hear a faint signal. So it seems that it is a fault on the board which
is affecting both playback and recording.

--
Tim Phipps

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