[Paul Dorman]

On 8/4/2020 12:12 PM, Neil wrote:
On 8/3/2020 11:13 AM, Paul Dorman wrote:
On 8/2/2020 9:32 PM, geoff wrote:
On 3/08/2020 2:59 pm, Paul Dorman wrote:
This was on a Roland Alpha Juno-2.

The original EL panel backlight was not working, so
I installed a new one, and although the back-light works
now, the LCD displays nothing.

Is it possible the new EL panel is slightly too thick, and
somehow causing the LCD display to lose contact with the main
board?

Thanks in advance for any advice.

Is the LCD on a ribbon, or some sort of blunt pressure-contact area
on the mainboard ?

Did you take full ESD precautions ? May have zapped whatever drives
the LCD segments or pixels.


Â*Â*Â*Â* Ok, I got it working again.

Â*Â*Â*Â* My hunch was correct:Â* The new EL panel was too wide,
and was insulating the flexible signal lines from making
good contact with the PCB board. No wonder it was so hard to
install the first time!

Â*Â*Â*Â* After I trimmed the new panel down thinner, it slid in
very easily, and the display works again.

Â*Â*Â*Â* Now I have only one problem left:Â* The aftertouch
doesn't seem to work?Â* After making sure the ribbon was
in good contact with the board, and measuring a change
in resistance at the main board, I was pretty sure it would
work, but it doesn't seem to be working.Â* Maybe I don't know
how to turn on the after-touch, with the global parameters?

Â*Â*Â*Â* Or maybe the resistance change I measured, was the incorrect
range, and the after-touch ribbon needs to be cleaned, and maybe
I need to clean the keys where they contact the ribbon?

Â*Â*Â*Â* At any rate, I was reading online that the after-touch on these
older synths tend to not work well after a while, and that many
people don't even like the after-touch anyways!

I would suggest cleaning the after-touch ribbon *and* the key contacts.
If the problem persists, check to see if the signal is being sent
(MIDI). Next steps would depend on the outcome
As for those who "...don't even like the after-touch anyways...", they
may not have a classic synthesizer background. It's just another
trigger, after all, and used for many things beyond fade-outs.


My customer accepted it as-is, without the after-touch, because
they won't be using it.