wrote in message
oups.com...
Hi there,
I found an old LCD module. I'm not sure if its working. Is
there a simple method to check if the module is working (without
connecting it to ,uc) , like using switches.
Thanks in advance

Well, I don't know exactly what your module is, exactly, but some of
the older, 7 segment digital LCD's maybe with the addition of a dash, comma
or decimal point could be checked with an old analog VOM. Put the VOM on one
of the higher resistance ranges, and use the test leads as a voltage source
to activate one segment at a time. One lead to the "back plane" and the
other lead to the segment being checked. (can't remember now which polarity
worked best..... won't hurt if you get it backwards first)
If you hold the module to the light just right, you may be able to see
which pin, land, or oxide plated area is connected to the segment you want
to test. The "illumination" or polarization (?) won't be at full contrast,
at all, and you may have to hold it at just the right angle to see it work,
but work it does! And if there is any contrast change at all with applied
voltage (with the correct polarity), there is a 99.99+% chance that segment
is OK.
Now, if it is a dot matrix LCD, this method may be not practical.
Additionally, if it is a module with built-in driving transistors, this
method will not work at all.
Old Chief Lynn