Re: Replacing LCD on QS8 (RESEND)

[ Follow Ups ] [ The QuadraSynth Forum ] [ FAQ ]

Posted by Previous Cut/Paste garbled Here is technical part again on December 13, 2004 at 13:45:02:

In Reply to: Replacing LCD on QS8 posted by Paul on December 13, 2004 at 13:43:15:


Alesis is ripping the public off in my opinion. They are charging
$59 for a $15 (or less) 2x16 LCD display, available from any number
of sources, including my favorite LCD supplier,
Check out the pictures of their products! Great colors and backlights.
Beautiful construction (no I don't work for them or know anyone who does).
You can get good LCD displays from many other places.

Suffice it to say you can get cheaper and prettier higher quality
displays than the hard (almost impossible) to find Data Vision LCD
in the QS8.

There is a catch if you want to use a standard LCD (and god knows
why Alesis didn't just use a standard part. Some sort of repair scam I think).
For some stupid reason the LCD in the QS8 has most but not all of the pins

Removing LCD:

Take off the top panel (black annodized sheetmetal) cover. Remove the few
(uppermost screws) on the back panel. Then remove the 6 screws (3 on
each side) holding the wooden endblocks on. The wooden endblocks are
attached to the top cover and they all lift off together to reveal the

Pry the LCD out gently with a flathead screwdriver. It pops out.
Snap in the replacement after you're sure you've got it working.

Making your cable:

If you want to use a standard (ie. Hitachi 44780 controller based) LCD in
the QS8 instead of the overpriced lower-quality stock part, you need
to make your own cable or adapter so you can swap pins, and also
adjust contrast and get power to the LED backlight. (All pretty trivial
with soldering iron and some \ 10K trimpot
LCD Pin 2 \
Vdd (+) -------

Experiment with the the resistor value (or adjust the trim pot) until
the LCD brightness is just right. I think a 330Ohm resistor
between pin 2 and pin 3 might work, but you might have to experiment
with the value.

Follow Ups: