From: PCBman (pcbman_at_ix.netcom.com)
Date: Wed Apr 02 2003 - 06:00:01 PST
Hi Anthony,
I looked at the problem and can see why it burnt up. It is the WRONG zener.
In the 'bad' unit I can see the motorola logo and 708 on the top.
This is a 1N708. It's a 500mW, 5.6V zener. That's the problem.
The Apple PSU is 7.5V. As soon as the PSU was plugged in, the zener would conduct. As it is connected across the supply - poof! instant toast!
The 'good' emate has a 1N713 in it. This is a 9.1V zener. That's much better. An Apple supply @7.5V nom. won't cause the zener to conduct under normal conditions.
I suspect the wrong zener was put in the 'bad' unit because it looked similar. But it's what's under the hood that counts.
The same size package could contain a zener with a voltage range from 2.4V - 200V. It's not enough to just be the same shape.
Anyway, Try 1SMB5924BT3 or equivalent.
Regards,
PCBman
-------Original Message-------
From: Anthony Velasco <ecotone_at_mac.com>
Sent: 04/01/03 08:47 PM
To: NewtonTalk <NewtonTalk_at_newtontalk.net>
Subject: [NTLK] eMate - replacement zener diode
>
This archive was generated by hypermail 2.1.5
: Sat Apr 05 2003 - 20:52:25 PST
> I have been working on resolving the typical hinge-related display
issues on Timothy's (a local NewtonTalk member) eMate. On his parts
salvage eMate (which was functional) we came across a different problem
that seems to be associated with someone plugging in an incorrect power
supply. I believe it is repairable. If anyone on the list has knowledge
of electronics, electronics supply vendors, and eMate specifications,
could you please take a look at the problem as we have it documented at
the following link?
<a target=_blank
href="http://home.earthlink.net/~avelascosprint/T-eMate.htm">http://home.earthlink.net/~avelascosprint/T-eMate.htm>
Thanks in advance for any help you can provide!
--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Anthony Velasco, USFWS-Ecologist/ecotoxicologist
ecotone_tv_at_hotmail.com
This Newt's trekking through cactusland and lov'n it!
Managing Sales and Licensing for Newton Software at:
<a target=_blank
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or <a target=_blank
href="http://www.tactile.com">http://www.tactile.com> <http://www.tactile.com/> - Tactile Systems,
Inc.
Contact me via the above E-mail for more information
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