"Joe Paulson" wrote to "All" (29 Jan 03  02:03:39)
 --- on the topic of "FIXSANYO"

 JP> For $3 at Goodwill,I got a Sanyo Radio/CD/Tape/2 speakers that
 JP> didn't work.Made in April.1955.It was a duplicate of one that I was
 JP> using and I might get some usable spare parts.
 JP>
 JP> When I plugged it in,nothing happened.
 JP> On opening it up,I saw a gray layer over part of the MB near
 JP> the 110 V.A.C. plug that looked like something vaporized.
 JP> My experience had been in tube circuit repair and I trying to learn
 JP> about what the new parts are.
 JP> The 110 V. power socket ( symbol CN ) was unusual with 2 pins for
 JP> the A.C. and 3 pins up to the MB (motherboard) where the center pin
 JP> was partially  missing.It looked like that this pin had vaporized.
 JP>
 JP> The socket looked like the following:
 JP>
 JP> -------------
 JP> I
 JP> 110V.A.C. -----       I
 JP> I-----I
 JP> ----              I \ 1    Pin 2 Partially missing
 JP> I \ 2
 JP> ------------------I \ 3
 JP> -------------------------------------------
 JP> MB
 JP>
 JP> Checking with an ohmmeter,there's no connection between the A.C.
 JP> and the 3 pins.The 3 pins terminate on the MB .What is this?
 JP>
 JP> I started checking voltages.The 110 VAC goes to a transformer and
 JP> steps down to 12.1 VAC. with a fuse in one leg,(still good) and
 JP> goes to a circuit of 4 diodes and 4 Caps.Checking the diodes with
 JP> the ohmeter,I get values from 1.0  to 2.2 megs,and nothing with
 JP> the leads reversed.The Diodes are "D", the caps are "C" ,
 JP> resistors are "R" as expected.I see that "L"
are coils,"CN" are
 JP> jacks.
 JP>
 JP> I noticed that there are wires running between tie points in the
 JP> MB with the symbol of "J".What are these? I thought the printed
 JP> circuit took care of connections.
 JP>
 JP> One side of the 12 VAC is also the B+ leg.?
 JP>
 JP> The radio has a connection for batteries (8 D cells= 12 volts).
 JP> I figured that if the power supply was bad,it could run on
 JP> batteriesonly and would verify the internal circuits.
 JP> When I connected the 12 V.D.C.,I started to see smoke and quickly
 JP> diseconnected.I felt around for hot spots and found one hot area
 JP> in the middle of the MB.
 JP>
 JP> I saw a L shaped metal separator,about 3 " long leg,3/4 " short
 JP> leg,about 5/8 " deep that was hot.Attached to it ,by a screw,was
 JP> a black piece,of several layers about 1 3/4 " by 3/4 " ,with the
 JP> symbolsToshiba TA 822?K with 14 pins going to the MB.
 JP> On the other side of the metal separator,I see a 25 V, 2200 MFD
 JP> cap.
 JP>
 JP> What does the symbol TA mean and is there any table of
 JP> descriptions on the Web? A look at the DIGIKEY catalog wasn't
 JP> helpful.
 JP>
 JP> If the B+ and one side of the 12 VAC are in the same leg,what
 JP> kindof a rectifier circuit is that with 4 diodes and caps?
 JP>
 JP> I also see another strange piece;
 JP>
 JP> bolt hole
 JP> v
 JP> --  ------------I metal support
 JP> --  ------------I
 JP> I          I \    The black item labeled "Q" was
 JP> I          I \    was held up by the 3 wires to the
 JP> -----------I \    MB.
 JP> -----------------------------MB
 JP>
 JP> Right now,my first inclination would be to replace the 25V,2200 MFD
 JP> cap and repair the vaporized wire in the connector and see what
 JP> happens.I still can't figure out where the current came from to
 JP> vaporize the metal in the center wire.
 JP> If nothing else,I could still use the parts as spares for the
 JP> good unit that I have.

The TA822?K with 14 pins is the audio amplifier and it is probably fried.
The TA prefix stands for a Japanese mfg system of identifing parts, in
this case an analog part made by Toshiba. The item labeled "Q" is a
power transistor, probably used to turn the tape motor on/off, or
alternately perhaps as voltage regulator. I'm amazed the fuse didn't
open up, maybe someone put in a much larger value. What values are
stamped on it? Let's try *not* to burn the house down, okay?

(BTW you should have posted this msg in Home Electronics.)

 Mike
 ****

... My God, exclaimed the Tagline, I'm in the wrong joke!
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