My car stereo is built around a Pioneer DEQ-9200. It’s a quite high-end, late 90’s sound processor with some nice features like auto-equalisation, a remote control and a three-group internal crossover. I like it a lot as it’s very seriously laid out, and aside from some pre-programmed EQ curves, it doesn’t try to be more “noob-friendly” than it needs to be.
There’s only one problem with it:
It’s hard to demonstrate the problem with pictures, as the level of light emitted from the display was so low in comparison to the buttons; it was hard to read even in a completely darkened room.
Upon taking the backside of the front panel off, one is greeted by two ICs, some passive components, two lightbulbs (the next thing to fail) and the solder blobs that supply power to the EL sheet that illuminates the display, as well as the “bendies” that hold the display assembly in place.
On the other side of the board, there’s an LCD display, some LEDs, an IR receiver (top right corner) and a whole bunch of buttons.
Underneath the LCD assembly, the white EL sheet is easily accessed. It’s merely taped onto the white piece of plastic with double-sided tape.
I’m going to use an EL sheet that I ordered from Electro-Luminescence Incorporated. They didn’t have anything that’d fit perfectly (22x108mm), but their 18x122mm sheet was the closest I could find anywhere.
I made the pressure connector by soldering two component leads onto the pads on the PCB, and simply bending them in under the sheet. It works a charm, as the LCD assembly presses it down quite snugly.
Since the sheet was just a little bit too small, I had to strategically place it to illuminate the most important part of the display. I chose the upper part, which houses the graphic and numerical displays, Auto EQ and posistion indicators. The lower part houses the pre-programmed EQ indicators and functions for the F keys.
Ia! Cthulhu fhtagn! It works! The above picture was taken in broad daylight, even!