It's good that you amazed by it, but a lot of boards are laid out in that
way with the sides labeled.
The optos are probably feedback for the SMPS, one might just be the one
controlling the fuser.
You'll probably also find a ferrite transformer or two straddling this
demarcation line.
When checking part numbers, don't use suppliers pages use google or
datasheet search pages they'll find much more.
ST
On Sat, 03 Dec 2005 14:51:42 +0100, lcdpublishing
<
lcdpublishing@...> wrote:
> Stefan, This one you will appreciate - please read.
>
>
> I was looking over the PCB for the printer trying to find the opto
>
> and the triac. I am studying it like crazy - components on one
>
> side, traces on back side trying to figure it out. It's not a dense
>
> board by any means, I am just stupid. Anyway, to figure out what is
>
> what, I would go to mouser and digikey and type in the part numbers
>
> of the various components - didn't help at all.
>
>
> So, while just staring at the PCB I noticed something interesting in
>
> the legends - the board is divided into two sections -primary and
>
> secondary. There are three, 4 pin DIPs bridging that outline and
>
> one big transformer. After thinking about that for a moment, I
>
> realized that those 3 small ICs are going to be the optos which
>
> isolate the primary from the secondary !
>
>
> Kinda neat how HP laid out the board like that. I will try to get a
>
> photo of it.
>
>
> chris
>