Glowing Zener Diode-Bad?
 

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

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Home Page: http://www.seanet.com/~jasonrnorth

Probably not. Does it still function as a zener?
"JR North" wrote in message
...
I know all diodes actually emit photons, but this tiny glass Zener is the
first one Iv'e seen actually glowing LED red. Is it bad?
JR

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Home Page: http://www.seanet.com/~jasonrnorth

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


I've seen diodes for voltage regulation which look like small signal glass
types, but actually glow red. Unless this diode is passing a large amount of
current, I suspect it's meant to light up. Does it get burning hot? If so,
then there's probably something wrong!

Dave

Some high end amps, & receivers, as well as rear projection
T.V.'s have diodes to give visual indication that a certain part
of the circuit is working, & has B+ power. Rono.


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

--
--------------------------------------------------------------
Home Page: http://www.seanet.com/~jasonrnorth

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


How do you know its supposed to be a Zener and not an LED?
As Rono pointed out surface mount LED's are common on PCB's and are intended
for the eyes of the service technician.


--
Graham.



%Profound_observation%

It's not SMT, and looks just like all the other glass diodes on the board.
JR
Graham wrote:


How do you know its supposed to be a Zener and not an LED?
As Rono pointed out surface mount LED's are common on PCB's and are intended
for the eyes of the service technician.




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Home Page: http://www.seanet.com/~jasonrnorth

It's not SMT, and looks just like all the other glass diodes on the board.
JR


OK, I haven't seen an LED with axial leads either, but I bet that's exactly
what you have there.

--
Graham.



%Profound_observation%

"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.

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

Does it have a reference designator silkscreened near it? LED's and
Zener's often, but not always, use designators other than Dxxx or CRxxx.
(LEDxxx, DSxxx, ZDxxx, Zxxx).

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

You may also want to look at this page, near the bottom:
http://ledmuseum.home.att.net/1990.htm

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All junk mail senders will be prosecuted to the fullest extent of the
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