On 28/07/12 18:33, Martin Ator wrote:
>
>
>
> If there is no pop and nothing on the display, or any other noises, then
> probably power isn't getting into the circuits. Any of the parts
> designed to protect against short circuit in the power circuit could be
> dead. The diode I told you about is a good candidate to start looking
> from. I have had to replace one in the past. If you have a diode test
> you can check this or just see if 9v is getting to the other side of the
> diode.
> I think it is the same as a 1N4004 diode.
http://www.oldcrows.net/~patchell/poly800/poly800.htmlCheck the 2SB744 "pre-regulator" regulator, which is in the negative
lead from the power socket.
D2 is just to protect against incorrect polarity.
--
Gordonjcp MM0YEQ