[R-390] need more help

[Barry Hauser]

I can see you're new aroun' here.

It's not the function switch, and they're generally not for sale as a matter
of principle.  Most other parts are for sale, but not function switches.
You can buy a panel with some stuff hanging on it, but not a function
switch.  And if you buy a panel, the microswitch may well be bad on it.

It is the microswitch on the function switch assembly that you need -- but
you don't need it yet -- and you can't have one -- yet.

It is in the hallowed tradition of R-390-ers (both A, non-A and hybrid) to
first attempt a fix of any defective part.  While it is customary outside
this circle to treat a microswitch as a "sealed unit", such notions are
eschewed, discouraged and basically run outta town on a rail, in these
parts.  That would be like stopping cold in one's tracks when encountering
the dastardly challenge:  "Do Not Open.  No user serviceable parts inside.
Refer to a qualified technician."

Most likely the contacts have fused in the microswitch.  Before I forget,
make sure the screwdriver operated switch in the back is turned to "Ovens
Off".  Don't ask, just do it and read up on it later.

So, unplug the receiver from the AC outlet, drop the panel (according to
procedure) and put an ohmmeter across the the microswitch terminals.
Operate the switch from off to standby to AVC, etc.  When going from off to
the other positions, it should go from open to nearly zero ohms.  Most
likely, it will read zero ohms in all positions.

If so, it's either because the contacts have become fused or the microswitch
position is not properly adjusted, such that it's always on.  Or perhaps,
there may be some gunk around it that needs to be cleaned away.  See if you
can make it make/break the connection by some studious fiddling.  (Fiddling
is a form of tinkering, and this is also required)

Does it click at all?  If it just needs to be adjusted, that will be
obvious.  If not, the next step is to remove the microswitch, take it apart,
being mindful of airborne springs, and free up the contacts.  Then burnish
them with a stick or something and treat them with some DeOxit (which you
are required to have).  Reassemble and test.  Some of them are put together
with small screws -- others are riveted, presenting a minor challenge to the
determined man with a drill.  Replace the microswitch, and carefully adjust
position so that it now works.  If you had to drill out the rivets, replace
with suitable screws and nuts.

Once you've tried all that -- and it still doesn't work -- submit a full
report, have it notarized, and then come back.

(Some people here and there have NOS microswitches.  Maybe Dave Medley.
Maybe Hank (Dan) Arney, or maybe you can get a used one from Fair Radio.  I
have two NOS switches, but you can't have 'em.

Y'see Scott, to better understand and get properly indoctrinated, follow
this guide:  An R-390 guy needs to fix a loose plank on his deck.  Needs two
10-penny nails.  Down to his last two, but one is bent and the other is
broken in half.  Go to Home Depot -- Naaaahhhhh!  Ace is the Place -- NOPE!
Straighten out the first one and weld the other one back together.  OK, a
little grinding to get it smooth enough to drive in.

It's not so much the money, more like the guy who climbs the mountain
"because it's there".  Heck, we'll even fix gassy tubes.  The broken ones
are more of a challenge because it's tricky to re-fuse the glass fragments,
and then a bit dicier to replace the vacuum.

Barry
PS -- did you read the "Pearls"


----- Original Message -----
From: "Scott Bauer" <odyslim@comcast.net>
To: "R390 List" <r-390@mailman.qth.net>
Sent: Tuesday, June 17, 2003 8:16 PM
Subject: [R-390] need more help


> Okay,
>
>  Does anybody have a function switch for sale.
>
>  Thanks,  Scott
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> R-390 mailing list
> R-390@mailman.qth.net
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