EntertainmentCommon

Clock radio or stereo

Also called boombox, clock radio, hi-fi.

Speakers, a transformer on the older ones, an amplifier, and knobs. The AM ferrite rod is a nice core. Cassette belts have turned to tar.

A donor is the dead machine. The parts below are what is still worth removing from it. “Leave it” is a part that is physically in there and should stay in there: too dangerous, too worn, or only useful as part of a repair you are not doing.

What you are looking at

A scrapped machine is a box of parts that failed at different times. The reason it was thrown out is often one bad piece. The motor, the cord, the supply, and the screws are frequently still good. This index says which is which.

Why it is in the trash while the parts are not

The CD mechanism died, or the style did. Speakers survive.

Before you open it

Do this while it is still unplugged, cool, and not leaking. Unplug. Old sets are mains, and some still have a live chassis. If the plug is not polarized and there is no transformer, stop.

Where the dead machine usually is

Living room and entertainment stack — In the house
Thrift store — Retail
Bulk trash day — Curb

Thrift stores. Heavier usually means a real transformer.

How it comes apart

Back screws. The speakers are in their own enclosures; keep the box if you liked the sound.

Tools: Phillips, Meter.

Words on this page

mains: Ordinary household wall power. It can kill. Unplug before you open anything that used it, and do not experiment on live wiring.
transformer: Two coils on an iron core. It changes voltage and, in a proper one, isolates the output from the wall. Heavy old adapters are this. Microwave oven transformers are a different, dangerous kind.

What to take

The table is the short version. The notes under it describe that part inside this machine, not only the general description.

Parts in this donor
Part	Call	How many	How often	Where to look
Speaker driver	Prize	2	always	Left and right.
Iron transformer	Prize	1	sometimes	Older radios.
Amplifier board	Worth pulling	1	usually	Main board or a module.
Potentiometer	Worth pulling	2–4	usually	Volume, tone, balance.
Ferrite core	Worth pulling	1	usually	AM radio.
Brushed DC motor	Bonus	1	sometimes	Cassette decks.
Indicator LED	Bonus	several	usually	Display.
Mains cord	Worth pulling	1	always	Rear.
Enclosure	Worth pulling	1	always	The cabinet.

Prize

Prize — take this firstSpeaker driver2 · always
Real cones, impedance stamped.
Left and right.
Unbolt. Keep the enclosure.
Foam surrounds may be dust.
Prize — take this firstIron transformer1 · sometimes
Iron, isolated, the weight in the box.
Older radios.
Measure the secondary AC.
Good if it does not smell burnt.

Worth pulling

Worth pullingAmplifier board1 · usually
A small audio amp. On old sets it may be discrete.
Main board or a module.
Keep the heatsink.
Scratchy pots are separate.
Worth pullingPotentiometer2–4 · usually
Log taper on volume.
Volume, tone, balance.
Scratchy is common.
Clean is a maybe.
Worth pullingFerrite core1 · usually
A ferrite rod antenna.
AM radio.
Fragile.
Good if unbroken.
Worth pullingMains cord1 · always
Inspect the strain relief.
Rear.
Old PVC cracks.
Inspect.
Worth pullingEnclosure1 · always
Wood boxes are the ones worth keeping.
The cabinet.
Plastic ones yellow and crack.
Wood is good.

Bonus

Bonus, if you are already in thereBrushed DC motor1 · sometimes
Capstan motor.
Cassette decks.
The belt is tar. The motor may be fine.
Belts are scrap.
Bonus, if you are already in thereIndicator LEDseveral · usually
Or a VFD.
Display.
LEDs are easy. VFDs are not.
Good.