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Jamie Jamie is offline
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Default PCB of garage door opener failed: Which PIC is this?

Joachim Wunder wrote:
On Sun, 11 Feb 2007 11:28:24 GMT, "Arfa Daily"
wrote:


No problem, at least we know what's going on now. I still would be reluctant
to believe that the bulb is going to have done anything directly to the
board, evn if it is connected to it by way of being relay switched. The
relay contacts are electrically isolated from the coil by virtue of
substantial mechanical separation.



That´s what I was convinced too up to the day when the bulb was blown
for the first time. Well, I´ll tell you something, I have one sheet of
paper which came with the PCB, but which only describes part of the
external connectors (i.e. actually only the ones which interface to
the motor on the backside of the PCB). The "funny" thing about is that
this sheet shows a very rough outline of the PCB´s external connectors
and mentions a fuse which is said to be there in the (N)eutral line of
the PCB´s power supply. Ha! I would be glad if there was that fuse
which is rated at 1A F(link). "F(link)" in German means with very
quick response time. And what do I see when I look at the backside of
the PCB? Ha! The manufacturer has simply left out the fuse and has
soldered a piece of wire instead of the fuse holder. Well done.

Fuse links don't need to be actual fuses that you recognize, they can
be special wire used, what looks like a resistor on the board or simply
a small foil path that is 2 half-moons with a small link of foil between
them..

--
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