Long time Ensoniq fan (The ESP16+ was my first keyboard every in 1991). I just purchased an ESQ-1. When it powers up the characters in the display flicker and are unstable. After a couple minutes they stabilize and settle into what is shown in the photo below. Everything seems to function. Keys, buttons, editing, sound is fine. I believe it does need a battery replacement (all internal patches show Brass 1). Is the screen issue a known problem and is there a fix?
• Tests already done (voltages, parts replaced):
I’ve tried reseating the ribbons connected to the display board with no change.
Do the buttons function normally while the display is flickering or only after it stabilizes ?
Quick Info:
The ESQ display has a dedicated processor chip on its board that communicates with the main board processor. It scans the pressed buttons and sends the to main processor and also receives the text from main processor and displays it on the VFD display.
CAUTION, BE CAREFUL of electrical hazards. Continue on your own risk.
If your don’t know or unsure how to diagnose a live/powered device, just don’t. You can still do basic troubleshooting with the keyboard completely powered off and disconnected from wall main power
If i have to guess, i suggest ::
Start with checking the PSU voltages,
Check for bad solder joint or corroded lines( check continuity)
Check the communication buffer chip
The display driver chips.
Bad caps near the dispaly/buttons processor chip.
If the buttons work while the display are flickering, i would focus on the display board; however, if they don’t then i would check the PSU. That delay might be caused by bad caps.
I had an issue where the display wasn’t showing anything and switches where not commanding any actions though the keybed
was playing just fine. The culprit was the buffer chip that sits on the display board and buffers the voltage levels between the display and main boards……there is a slight chance that same buffer chip acting up.
I don’t think there is an eeprom on the ESQ-1. All the buttons function normally. it’s just the garbled top character grid. New development- after letting it sit powered on for several hours, the display cleared up. I believe the previous owner had it in storage for many years. After the initial warming up period, the display clears up (after being turned on again) in a matter of 20-30 minutes or less. I don’t know what that suggests? I have little electrical experience.
