Zener diodes are made to break down with reverse voltage
If you put a ten k resistor in series and then apply six volts with a power supply in the reverse direction, it should be easy to tell what is a 4148 and what is a zener
Assuming the zener voltage is five or less
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On Wed, 2/10/16, jw_dewdney@yahoo.com [PolySix] <PolySix@yahoogroups.com> wrote:
Subject: Re: [PolySix] Re: The Post I wanted to make....
To: PolySix@yahoogroups.com
Date: Wednesday, February 10, 2016, 10:47 PM
well it's great that
you mentioned that - I THINK I spotted a ZENER instead of a
1N4148 at D3.... though it's a bit hard to tell them
apart... Perhaps a ZENER got into my signal diode drawer
somehow (understandable!) .. although it didnt' make
much of a difference in the end result... so i'm just
circuit tracing around now - one WEIRD thing i noticed is
that the ground plane of the top of the board is not
connected to the ground plane of the bottom (apparently by
design?) - odd... on the other side of the board it's
connected to CN10's +5V pin....