22 Apr 2003, 00:41, Charles Angelich (1:106/2000), wrote to Matt Mc_carthy:

Hi Charles.

 MM>> Hmmm... "It hummed with the switch off...", and "The right
 MM>> side works...". 

 MM>> It all looks to me like the 9V power unit was DC which the
 MM>> speakers were looking for, and the 12V power unit was an AC
 MM>> one.  :-(( 

 CA> Could be AC but if it is it's incorrectly marked as VDC? 

Hmmm...  Haven't run into that yet.  UNmarked is another story though.

Now, to get AC out of a unit marked DC (assuming a bridge rectifier), two
of the diodes would have to be shorted, and the opposite two would have to
be open.  That sounds about as rare as "world peace in my
lifetime".  

OTOH, if it was DC but reversed polarity, why the "hum with the
speakers off", and why did it happen to only one side?

I'm stumped on this one!


     Good luck...  M.

--- Msged/386 TE 06 (pre)