"Arfa Daily" wrote in
:
"Joachim Wunder" wrote in message
.. .
On Fri, 09 Feb 2007 03:15:46 GMT, James Sweet
wrote:
Joachim Wunder wrote:
Hi there,
I have a garage door opener named "Liftboy SMD 3200" which was
installed into my garage back in 1990 (in Germany). I couldnīt get
any information about this garage door opener on the net. The motor
control PCB of it just failed this week. I suspect either any
capacity or the voltage regulator to be the culprit. Does anyone
know the manufacturer of the PCB shown under
http://img255.imageshack.us/img255/9023/cimg0094aq6.jpg ?
Unfortunately, the 40-pin PICīs type isnīt readable under the
sticker at all īcause its surface seems to have been scratched off
under the sticker by the manufacturer of the PCB. Yagh. Which PIC
is it supposed to be? There is a Quartz which reads "4.000 SUNNY
7624".
Moreover, the same applies to the 16-pin IC: Itīs surface seems to
have been treated by the manufacturer of the PCB, i.e. the exact
type has been completely scratched off on purpose as well. 
Is
there any way to find out which IC it might be?
Please advise.
TIA,
Joachim
No, the filter capacitor is not shorted, I just measured it. Hmmm.
As long ago as this was made, I2C was not a common bus scheme ( if it
even existed at all ) and in any case, what would want to be
communicating over such a bus in a simple door controller ?? The
regulator can be checked out of the board by applying any voltage over
about 9v between the left pin ( +9 ) and the centre pin ( 0v ), and
measuring the output for +5v between the right pin and the centre pin.
This is with the writing towards you or metal tab away from you.
However, you are never going to get to the bottom of this board's
problems by being afraid of it. A bulb blowing across the primary of
the Tx, is highly unlikely to have done any damage to it, and even if
it had, what is going to be the problem ? An o/c primary winding ? No
problem, the board just won't do anything. A s/c or shorted turns
primary ? No problem - it'll just blow the mains fuse, or smoke. No
matter what, it doesn't work now anyway, and you have no clue why
unless you put some power on, and take some readings. It could be
something as simple as a bad power supply circuit - one of the reccies,
or the 5v regulator, or yes, the tranny even, but unless you build up
the courage to put some power on and see just what's going on, you're
never going to know. Anything we suggest at this point, is really just
useless conjecture, yes ??
Arfa
Yes. Does the motor work? Do the relays switch? Are all the Diodes
functional? What causes you to suspect the IC's? Are you just whistling
in the dark because the voltage regulator that normally gets hot has
discolored the circuit board it sits under? Without actual
troubleshooting you are not going to get anywhere...
----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption =----