A relatively common problem on older equipment, is the failure of the LCD backlight (or EL-panel). Often accompanied with a very high-frequency whine emanating from the LCD area of the gear in question, it's time to consider LCD backlight replacement.
Here's a Roland GC-8 editor / controller for the massive Roland R-880 reverb (circa 1988). Without the controller, the R-880 which really is an awesome machine, is kind of useless as there's little out there to program it via MIDI.
Luckily and thanks to a company called backlight4you, LCD backlight replacement is now worth looking into. A variety of EL-panels that are suitable for a whole bunch of older gear, is available at the company's website which is also full of other useful and related information. Their backlights are reasonably priced and arrive from Germany pretty quickly and in very stiff cardboard packaging.
After fitting the replacement EL-panel, I powered up the unit to check. Wow! It looks great and on this occasion I got lucky and that bloody annoying whine has gone!
IMPORTANT: As a backlight ages, its electrical characteristics change, These changes put a strain on a small component called an inverter which converts dc within the unit to high-frequency ac which is required to drive the EL-panel. As this component deteriorates, it starts to whine. In many cases, replacing the backlight will fix that problem but... not always. : (
If after swapping out your backlight, your unit is still whining, then backlight4you may still be able to help. Take a closer look at their website and you'll find a section on inverters. Designed to run from common voltages and power many of the EL panels that are sold on the website, these replacements are very reasonably priced.
Replacement inverters might not be pin-for-pin compatible, especially with very old equipment but with a little ingenuity, you might be able squeeze one in somewhere.
Due to the low cost of replacement inverters, I would personally recommend swapping out the inverter if possible, when fitting a new EL-panel.
Need help with a hard-to-read LCD? Drop me a line.
UPDATE - 20th May 2020
Several days after replacing the EL backlight panel in this Roland GC-8, the high-pitch whine started again. I decided to go back to backlight4you and check out the inverters that are advertised on the company's website.
Due to the limited space inside the GC-8, I needed something small and indeed the backlight4you inverters do look as small as you can get them.
While waiting for the inverter to arrive, I removed the original transformer from the GC-8 inverter circuit. This is the components that actually generates the whine.
When the inverter arrived, I placed underneath the main PCB towards the sockets at the back. Phew! It just fitted.
Of course it wasn't possible to mount the 3-terminal inverter directly on to the PCB but using a few pieces of wires, connecting it was pretty straight-forward. I then secured the epoxy resin inverter block to the case with a little double-sided tape and surrounded it in hot glue.
It's important to note that this is a complete inverter and NOT just the transformer.
Time to power up and test. DEAD quiet! Definitely worth doing.