TH215.3

Date: 05 May 90 13:41:36 UTC (Sat)
From: wa2ise@kd6th.nj.usa (Bob)
Message-ID: <25694@KD6TH.NJ.USA>
Subject: a TH215 no audio fix


Newsgroups: rec.ham-radio
Subject: Re: Kenwood TH-215A no audio problem
Organization: Hewlett-Packard Co., Corvallis, OR, USA

PROBLEM:
>In a sample population of about 60 amateurs in this town, three of us
>own Kenwood TH-215A HT's, all purchased separately at different times
>from different sources....

>ALL THREE have developed an audio problem in the last eight months:
>the audio (both from the microphone and from the keypad) simply
>disappears at unpredictable intervals.  And all three can be "fixed"
>by WHACKING the HT with the palm of one's hand--until it happens again.

A POSSIBLE FIX:
 You guys may be in luck, since I fixed mine -- I have the service manual
and decided to jump in (I had upgraded the software and you have to pull the
unit completely open to do it -- ). Anyway, I was using the rig one day and
the next -- no audio -- just a slight noise that appeared to be white noise
from the final audio buffer. When plugging in the speaker mike -- same
problem. Touch the TTPAD and get your ears blown away -- I think beep also
worked. Kenwood had no knowledge of previous problems.

I had to rig-up a jumper ribbon cable so I could lay the rig out for
testing and immediately checked the input audio to the volume control.
No problem -- but there was nothing coming out the other side. I
jumpered the pot (i.e. simulate pot max volume) and my ears were
hurting. Upon removal of the pot I found a crack on the ALPS pc board
that has the leads mounted to it. Apparently, I must have hit the
volume control pot the previous day and cracked the pot trace (again
this trace was part of the pot not the rig pcb). I had noticed when I
disassembled the unit that there was no nut on the pot to hold it in
place (none on the squelch either). The volume pot is right at the edge
of the unit and is the most likely knob to get hit.

When parts arrived, it came with a nut so I installed it to help prevent
this problem in the future -- no problems since.

I think the switched volume pot cost $4.95 + $3.00 shipping.
 I also picked up a set of backcase screws -- very small
heads but very long screws to replace my old ones -$.05 - Make sure you have a
"good" screwdriver that really fits.)

All these problems sound like the same thing. I have never had any problems
with my rig, and I bought one of the first ones out. (Hence, the software
update to give me the ability to lock out memory channels during scan.)

Hope this helps.

Greg May
gregm@hp-pcd.HP.COM

Note: I haven't tried or verified this, proceed at your own risk! WA2ISE

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