[sdiy] rotary encoder failure mechanism

[Chromatest J. Pantsmaker]

I've replaced/repaired encoders in Pioneer CD players (the DJ kind
with the big jog wheel) and in the pioneer DJFX-500 boxes.  The DJFX
use an optical encoder if I remember correctly.  Either way, I had no
problem carefully opening it and cleaning it out successfully.

On Wed, Feb 3, 2010 at 2:08 AM, Neil Johnson
<neil.johnson97 at ntlworld.com> wrote:
> Hi,
>
> Dave Manley wrote:
>>
>> When an encoder becomes unreliable is it because
>>
>> 1. the switches are worn out
>> 2. the switches are contaminated and need cleaning
>> 3. the mechanical cam that operates the switches is worn out
>> 4. debris from wear on the cam/switches is blocking the switch operation
>> 5. ???
>> 6. any and/or all of the above?
>>
>> Anybody take one of these apart and do an analysis?  Does spraying cleaner
>> into an encoder really do anything?
>
> The low-cost ALPS style rotary encoders (e.g. as used in x0xb0x) are built
> in same way as their pots: a little PCB with tracks printed/etched on them,
> and the spindle moves sprung metal contacts over the tracks.  Pots have
> single or dual carbon (or some other resistive material) tracks, encoders
> have highly conductive patterns to implement the A/B codes.
>
> Otherwise same materials, same lifetime, similar failure modes.  No cams or
> anything like that.
>
> Neil
> --
> http://www.njohnson.co.uk
>
>
>
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-- 
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-Chromatest J. Pantsmaker
http://www.chromatest.net