Re: Surface mount diode identification


captainvideo462002@xxxxxxxxx wrote:

The board is a fire alarm main board and is manufactured by GE
Security probably off shore. These diodes could be anyones I guess.
The thing is, this exact failure, that is these two diodes shorting
out has happened many times before on this security installation. It
usually occurrs after a bad lightning storm. For the time being GE has
repaired these units under warranty but the warranty period is coming
to an end. These boards are no longer in production so it also
involves sending the board out for repair and so the premises are not
protected during that period. I would have to guess that at least one
of these diodes is accross the input reversed biased to ground because
when it shorts out the unit displays "Ground fault" and the zone is
knocked out of commission. Would you think that this is probably a
zener or perhaps just a standard run of the mill diode? Lenny


Lenny, you should check the liability of repairing fire alarm
hardware without the OEM's blessings. You may end up assuming all
liability if something goes wrong. If the laws haven't been changed,
any repair other than replacing a failed board with anything other than
a factory built or repaired assembly makes you liable for future
losses. When I investigated this years ago I was told that I needed the
original OEM service data, and a minimum of 10 million dollars in
liability insurance. I'm sure it has gone up, over the years.


--
You can't have a sense of humor, if you have no sense!
.

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