Well I finally got your photos Inge! Don't have a clue why it took so long,
and don't know why it took multiple tries to get your photos. Did you try
both my work and personal email addresses? Very strange!
Anyway, here are your photos. I have never seen such a pile of shit! I
understand the true meaning of IPC Class-I electronics now. All my
instructors have emphasized during certification classes that Class-I
electronics only have to work once. There's no requirement for them to work
beyond the first time they are powered up. But I think what you are showing
us pushes the limit of how terribly something can be made and still be
called a Class-I assembly!
From your pictures it looks this board was assembled (if you can called it
that), and then put into it's plastic case with a very corrosive flux left
on the board. They probably had to use a very active flux to get the solder
to wet to anything on that crap!
Here's the links to your photos. I must caution everyone not to click on
these links if you have a queasy stomach. What you are about to see is
pretty stomach churning!
http://stevezeva.homestead.com/DSC_8741b.jpg
http://stevezeva.homestead.com/DSC_8743.jpg
http://stevezeva.homestead.com/Kopia_av_DSC_8744.jpg
http://stevezeva.homestead.com/Kopia_av_DSC_8745.jpg
http://stevezeva.homestead.com/Kopia_av_DSC_8746.jpg
Steve
-----Original Message-----
From: Inge
Sent: Thursday, January 13, 2011 6:06 PM
To: [log in to unmask]
Subject: [TN] a different Friday quiz
I bought a digital temperature equipment, consisting of a inhouse table unit
and a outdoors unit. Cost = 25 USD. Cheap? Yes. But let's have a look on
inside after the problem, which started just a few weeks. You can read the
inside temperature, clock works, date works, and you can use the alarm and
shift between the four channels, but the receiver does not take in the
signals from the little sender on the wall any more. I dismantled the box
and marvelled when I saw the shit I payed for. It's a wonder that there are
any functions working at all! Now, what caused the dead receiver was a flow
of iron from one screw (upper left corner ) . There is a bridge of
corrosion products (brown and green) from the screw to the thermistor (RT)
continuing to the rest of the circuitry. When I washed the card and dried
it, the reciever worked again,
Now, folks, here comes a question for the sharp TNetters:
"How can the screw be so rusty and deliver iron ions when it's not connected
to anything? It's just torqued into the plastic body. The other screws are
identical, but have not been involved in anything. "
The box has been on the kitchen table and has not been exposed to humidity
or any else abnormal condition.
The two 1.5 V batteries are removed on the pics.
Hope the gregorian Steve will help me with the photos.
/Inge
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