Odd Software for Odd Jobs

Adding AUX-IN to my "boombox"

We've got an "old" Sony CFD-S350 portable radio/CD/tape player (i.e. a "boombox"). So it doesn't really get much use any more - but if it had an AUX-IN then we could hook our MiniDisc or iPhone … or anything … and still use it.

2017-04-23 05.07.12

Pulling it apart …

2017-04-23 21.13.10

Disconnecting the flat flex connecting the CD unit and button controls from the main controller board

2017-04-23 21.12.22

2017-04-23 21.09.18

Removing the tape unit and speakers to reveal the radio tuner board …

2017-04-23 21.07.43

I still want to play the occasional tape and CD … but I don't really listen to radio, so let's see if there's something there I can use …

2017-04-23 05.07.12-3

(I've noticed that the Japanese use the Icelandic letter Ð instead of just plain D … makes sense as it prevent confusion with the letter O or digit 0!).

So there is a left & right channel coming into the main controller board (and amplifier I assume) that I could connect my AUX-IN to!

This is the radio tuner board with the flat flex connector on the right.

2017-04-23 05.07.12-2

The IC is a Toshiba TA2149-series … and the data sheet tells me these are the R & L channel outputs:

2017-04-23 14.04.40-1

Following the trace confirms that they run directly to the flat flex connector with nothing else in the way:

2017-04-23 14.03.33-1

I found the service manual for the CFD-S350 and noticed that there are two 0Ω resistors being used as links … so I could simply remove them, disconnecting the decoded audio from the radio tuner chip and hook my AUX-IN socket:

2017-04-23 17.39.18

Careful …

2017-04-23 20.50.14

Now hooking in my AUX-IN socket …

2017-04-24 13.08.44

Drilled a hole in the side of the case for the socket and put everything back together:

2017-04-24 17.11.46

2017-04-24 13.11.22

New life/use given to this still-working-fine piece of equipment!

2017-05-03 09.37.35

Bonus point … there's a 2Kbit CAT24WC02 serial EEPROM on the the underside of the main controller board … IC805, top right … that uses the I2C bus. I wonder what's on it … ? Maybe I could use an Arduino to read the contents?

2017-04-24 12.36.10