No Display on ESQ-1 and SQ-80

Synth Repair
1

I have 2 boards, ESQ-1 and SQ-80 with similar issues. Blank screen.
I have the repair manual for both and have followed the procedure for testing the display. For both situations I end up with “replace the display/keyboard”.
I see Syntaur has display board for ESQ-1 available, so may try that. But I’d like to try and see if I can reapir both boards. So any idea if this may be the display itself or the processor.
I have tried to reflow the board, but with no success.
I see that replacement processors can be aquired from [www.buchty.net] Section Ensoniq
Item: BMD65003
Other Ideas are more than welcome :slight_smile:
Martin

1 Like
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Firstly both of these boards are tricky to repair for beginners. Before you do anything check the fuses in the power supplies! If all good here check the voltages on the output side, but be very careful that you don’t short anything in the process. Then make sure all the cables are plugged in properly by reseating then firmly. The ESQ1 will have a blank screen if you have issues on the mainboard or the display board. The SQ80 will give you the same thing if you have a problem on the mainboard, display or KPC board that sits underneath the keybed and reads the keyboard. The lucky thing is that a lot of the parts are interchangeable between the two. The display boards are the same, also a lot of the main chips which are socketed on both machines are too. The CPU, DUART and the DOC which is the sound chip. In both machines the DOC is the boss and if it’s faulty the whole mainboard won’t run. Assuming that you don’t have a faulty DOC in both machines I would swap the two chips around as a first go. Using a marker I would mark the chips before removal and use a piece of paper to write down what you have done to not get confused. Also between tests I would put back the swapped parts back in their original machines. I would then do the same with the DUART and CPU. I would concentrate on trying to get the ESQ1 to run first because it’s simpler. Good luck

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Check out an Ensoniq repair shop that specializes in only Ensoniq keyboard and products repair. I may also send them my Ensoniq ASR 10 keyboard. Go to google and type in:
www.thesoniq.com
The technician that runs it has all the Ensoniq parts and used to work for Ensoniq. It’s also an authorized repair for Ensoniq keyboardss exclusively. I hope :pray: this helps you out. Good luck :+1: :+1: Sincerely, Mike D.