I was at the local surplus dealer and they had the zener diodes organized by
zener voltage. Would a 8v2 be a 8.2v zener?
Thats what I got and it seems to ohm very close to what the good zener ohms.

The actual part number for the zener that I got is 1N5237b738.

Thanks for all the help Arfa

- Mike

"Arfa Daily" wrote in message
...

"Michael Kennedy" wrote in message
...

Is that black stripe a genuine paint one on the outside of the diode, or
a
Yes I believe it is genuine paint. It is on the other diode which has not
failed.. I guess I could find out what kind of zener diode it is by
testing it as you said, but I have never done this before.. I guess it
is time to learn.

Here is a picture of the working diode (ZD2 not ZD1) up close and in the
sun so you can really see the colors..

http://mikescomputers.homeip.net/LCD/DSC00386.JPG

Close-Up

http://mikescomputers.homeip.net/LCD/ZD2.JPG

Thanks,

- Mike


OK. Looks like a genuine paint band. I'm still up for it being 8V2 though,
if for no other reason than it's a very common value, and corresponds to
the other two stripes. If what ever the unit is, is working at all, then
just check the voltage across the non-blown diode. If the unit is not
working, you can test the other diode for voltage rating easily enough, by
removing it from the board and hooking a resistor - say 4k7 - to its
cathode. Then put 12v across the combination, "+" to the free end of the
resistor, "-" to the diode's anode, then measure the voltage across the
diode. Any reading up to about 11v, will be the zener voltage. If you get
a reading of 11v or more, then the diode hasn't 'zenered' and you need to
up the voltage across the combination a couple of volts at a time, until
you do get a steady voltage, that doesn't increase any more, as you
continue to up the voltage. You've then found the diode's zener voltage.

Arfa