Nakamichi Radio Repair
 

Hi,

I have a Nakamichi Table Radio, Model TM-1. Sleek, black, with bright green
read-out. Purchased at Tweeter over 10 years ago.

Problem: Pluged into the A/C, it immediately starts low level buzzing sound
through the speaker. The radio is not even turned on yet. The On/Off button
is a PRESS_DOWN button on top of the uradio. Its not an on/off volume
control knob, which exists on many radios.

Pressing the ON/OFF button changes nothing, regards the buzzing. None of the
controls seem to do anything different. There is a volume, Bass, and Treble
control on the side. Turning any of those knobs does nothing different. It
just keeps that low buzz buzzine sound.

I am not very knowledgeable about repairing electronics. I did open the unit
and inspected it. It opens in two halves. There are three cables that join
the two halves. They are easily detatched (nice design). One side contains
the circuit board with the A/C transformer bolted to it. The other half
contains the led unit and the ON/OFF, plus other controls, switches, volume,
bass, trebble, etc. I took apart the module on top where you press down on
the on/off buttin, and checked that the on/off detent works (actually does
press down and makes contact) when you press down on the top Power on/off
button.

Where do I go next?

Pat

Nakamichi Radio Repair
 

When you are inexperienced with electronics I fear my hint won't help much,
but anyway:
A constant humming doesn't really need to come from the electronics itself,
but could be very well induced from the transformer.
The other spot to start is the capacitors in the powersupply, usually quite
large ones. When the unit humms / buzzes , it is quite often that these
lost a part of their capacity, thus letting low frequencies pass they
should have absorbed usually. So step one is to replace them. Usually
choosing cap's one scale larger doesn't hurt.


Pat wrote:

Hi,

I have a Nakamichi Table Radio, Model TM-1. Sleek, black, with bright
green read-out. Purchased at Tweeter over 10 years ago.

Problem: Pluged into the A/C, it immediately starts low level buzzing
sound through the speaker. The radio is not even turned on yet. The On/Off
button is a PRESS_DOWN button on top of the uradio. Its not an on/off
volume control knob, which exists on many radios.

Pressing the ON/OFF button changes nothing, regards the buzzing. None of
the controls seem to do anything different. There is a volume, Bass, and
Treble control on the side. Turning any of those knobs does nothing
different. It just keeps that low buzz buzzine sound.

I am not very knowledgeable about repairing electronics. I did open the
unit and inspected it. It opens in two halves. There are three cables that
join the two halves. They are easily detatched (nice design). One side
contains the circuit board with the A/C transformer bolted to it. The
other half contains the led unit and the ON/OFF, plus other controls,
switches, volume, bass, trebble, etc. I took apart the module on top where
you press down on the on/off buttin, and checked that the on/off detent
works (actually does press down and makes contact) when you press down on
the top Power on/off button.

Where do I go next?

Pat

--
Sincerely
Aries Quitex
http://aries.eu.cx http://wanted.freesubs.de
Advanced Architecture - OS3.9 & GeForceIV =)