"JR North" bravely wrote to "All" (25 Sep 05 23:33:32)
--- on the heady topic of "Glowing Zener Diode-Bad?"

JN From: JR North
JN Xref: core-easynews sci.electronics.repair:343144

JN I know all diodes actually emit photons, but this tiny glass Zener is
JN the first one Iv'e seen actually glowing LED red. Is it bad?


If it's hot "too" that is bad.... or not, get out the marshmallows!
Seriously, perhaps it is a LED being used as a Zener. What is the
voltage and package type markings?

Many zener types are encapsulated in black or painted, thus if they
glow they aren't often seen. Basically many junctions can emit light
and led's were an accidental lab find.

A*s*i*m*o*v

.... I worked hard to attach the electrodes to it.