esq-1 issue

[elsquirrel]

Got a cheap esq-1 recently with 'no issues'..... naturally its full of problems.

One of which is that the screen will go blank after a while. I can still play keys and they sound but they screen won't return. Pressing the panel buttons causes different characters to come up on the blank screen. The only way it seems to get back to normal is to turn it off then on.

I reinitialized using PROGRAM + button 1, and I thought that worked but it just happened again. I had a look inside and everything seems to be seated fine and nothing obviously untoward. Anything else I can try?

It's only os 2.3, if that makes a difference.

thanks!

[rhino]

Welcome to the board!

The fact that buttons cause characters to appear on the screen means the display has gone into "self-test mode". Generaly means that the serial connection between the mainboard, keyboaard and display has been lost.

First thing is to unplug and clean the cable connectors on the display (3), keyboard (1) and mainboard (2).Serial data is constantly being passed around this "ring" and even the interruption will stop the display.
'Early Ensoniqs used a prro quality plating on their connectors - tends to oxydise. Use a good contact enhancer like the stuff from Caig.

[elsquirrel]

HI,

Thanks for the welcome rhino, though I joined two years ago!
Actually, I think you helped me with a problem I had with the first esq-1 I bought back then.

Going to give all the connectors a clean. I still have the caig stuff I bought for cleaning the the key contacts on my other esq-1. And know that I think about it, I'm pretty sure at the time I cleaned the connectors on that one too, so I don't know why I didn't think to do it this time.

Do you have any experience changing the os eproms? I noticed on mine, which is the metal version, the chips are underneath the keybed, but looked seated like the photos I've seen on the plastic model. Guess all I need to do is pop them out, but I was a little confused because I keep reading that you need to desolder the chips from the older metal versions. Maybe their was an in between model?

[rhino]

Yeah, well... Two years is about my memory span.
Changing OS chips is no problem:
1-watch for bent pins
2- Don't mix the HI and LO chips

Worked on many ESQ-1s... never found one with OS chips soldered in.

[Silverfish]

If reseating the connectors doesn't solve the problem, it maybe time for a power supply recap.

The power supplies on Ensoniq boards are probably the weakest link on these things, and can cause all sorts of weird issues. They're all about at the age where they''re going bad, and now Ensoniq boards are dropping like flies. Replacing capacitors isn't terribly challenging if you've soldered before, and it can totally save an otherwise non-functional synth.

Good luck!

[elsquirrel]

Thanks for the help. I cleaned everything and she seems to be running smoothly. Just waiting on a new battery and OS upgrade to arrive.

In regards to the pedal/cv input, I've tried to use the trigger outs of my 606 and couldn't get any result. I wanted to try and modulate the freq cutoff like I can with the juno 6. I'm really not familiar with the technical aspects of cv, according to the manual, the cv functions under the following specs:

3-conductor (tip=control voltage input, ring=2kOhm resistor to +12 volts, Sleeve=ground) 500Kohm input impedance DC couple, input voltage range=0 to 10 volts DC Scan voltage, use a 2 conduction cable with the voltage tip and the sleeve grounded.

The 606 is apparently: +14 V, 20 ms pulse.

Is possible for them to work together?

[elsquirrel]

I cleaned every connector, changed the battery and installed the latest os eproms. Unfortunately it still goes into the self-test mode at random times. Makes for 'exciting' programming not knowing when you might lost what you're working on. The buttons also become non responsive for short periods of time now. You can play the current patch but no buttons respond for 10secs to 1 min.

I'll clean everything once more and then after that I guess I'll try the power supply recap route. Anything else I might be overlooking?

[Shleed]

Probably a PSU issue.

[rhino]

Butting in again. PS problems usualy cause random resets. You say the synth will keep playing from the keys even though the display is dark. Try replacing the 74LS04 hex inverter (IC1) on the display board. Also, check and re-flow any suspect solder joints on that area - including the two connectors to the PS and mainboard. The ESQ-1 uses the same regulators for both the mainboard and display, so failure of either would p'bly kill the sound.

[elsquirrel]

It's pretty much unresponsive to button presses now and the screen goes blank pretty often, though doesnt reset on it own and you can always play sound from then keys.

I see the part you mention rhino. So you think replacing that is the next step? No idea how to deal with psu if that's the problem. It's heading for the scrap at the moment.

[musichascolors]

I'm experiencing very similar issues on my ESQ-1. Wonder if elsquirrel got it resolved.

[Rasputin]

That problem shouldn't have been that hard to fix. I'm pretty sure Rhino was dead on that it was the connector from display board to the mainboard. Hard wiring it (soldering leads) instead of a harness would be the next thing to try. The only other explanation I can come up with at the moment is a flaky UART or that the leads were passed over a noisy chip with high RF.

And it's clearly working at certain times, so it's not as if any non-replaceable parts are dead. Definitely doesn't warrant the scrap heap.