dead keys esq-1

[elsquirrel]

Hi,

I'm looking to for an esq-1. There's one currently on ebay in my area: http://cgi.ebay.com.au/ws/eBayISAPI.dll ... TQ:AU:1123, though it has issues with three keys. According to seller:

No sound from the last 3 keys at the highest octave (on the right end of the keyboard). May be due to programming or soundset. Hubby thinks this is the reason but not 100% sure and no time to figure it out.

Anyone familiar with the esq-1 who can comment on this problem. Is there an easy way to test if it's mechanical by resetting factory patches or something similar? Could a dead or dieing battery cause keys to die?

[rakk95]

Doubtful that it's programming.

I just got done fixing eight dead keys on an old metal-case ESQ-1. They were grouped in pairs spaced eight keys apart. Turns out it was a result of someone spilling coke or some other corrosive drink on the keys years ago. The PCB traces around middle C eventually ate through, killing the keys above the broken connections (the encoder scans the keys in groups of eight, which accounts for the regularity of the groupings).

If you're technically inclined and want to chance buying the ESQ, you'll have to remove the keybed by removing the ten or so screws that hold it to the metal case (they're on the bottom of the unit). Carefully lift the keybed up and out of the case, and carefully disconnect the ribbon cable, taking care to note the orientation of the connector.

Examine the key contact springs on the top three notes (the FATAR keyboards on these units used brass springs to contact the upper and lower contacts, the idea being that they would self-clean. It worked so-so). Try cleaning the springs with contact cleaner first (Deoxit works best on the oxidized brass). If this doesn't work, you'll have to do some more adventurous work...

There are small nylon holders underneath each key that hold the key contact springs. You can mess up a spring if you're not careful. I unscrew the spring holder then carefully pull it off (one at a time for 61 keys). Carefully remove the nylon holder from the spring, taking care not to over-stretch the spring. Once they are all removed, you can remove the printed circuit board by removing the screws holding it on. Remove the PCB and turn it over. Examine the PCB traces and solder joints.

If this ESQ has the same issue mine had, the PCB traces are cut between the upper three notes and the three keys 8 down from them (if I'm correct, the top three keys will correspond to the Eb, E and F keys just below them). You'll have to run three jumper wires from the back end of those three diodes to the top Bb, B and C diodes.

Let me know if you want to attempt this, and I'd be happy to help walk you through it. If not, I recommend you find a qualified tech....or a fully-operational ESQ!

regards - DY

[elsquirrel]

Thanks for the reply.

Probably leaning towards holding out for one that's fully functional, just thought maybe there was something I could ask them to check. Good info though if I ever run into the problem again. Cheers.

[drjay51]

I have a similar problem, my ESQ1 has an intermittent key issue. While playing some keys will not speak or sound when you hit them, hit them again and they work. It's not the same keys, it's random in order and it's not all the time, it's intermittent. So I'm guessing it's the key contacts. I have been told that various contact cleaners can do more harm than good. Is Deoxit safe for the plastics and rubber and will it eat or dissolve the tarnish on the key bus wires as well as the brass springs? I've tried alcohol and it doesn't touch the grunch. Any suggestions are welcome.

drajy51

[rhino]

I have a similar problem, my ESQ1 has an intermittent key issue. While playing some keys will not speak or sound when you hit them, hit them again and they work. It's not the same keys, it's random in order and it's not all the time,
drajy51

Are you sure you don't have a dead voice or two? Play chromaticly up or down the keys: If every 8th note fails, or if the dead keys are 8 notes apart,(that is, if two or more notes out of every 8 fail) then you've lost a voice. )or two)
IIRC it uses the CEM 3379 chip.

[rakk95]

I have a similar problem, my ESQ1 has an intermittent key issue. While playing some keys will not speak or sound when you hit them, hit them again and they work. It's not the same keys, it's random in order and it's not all the time,
drajy51

Are you sure you don't have a dead voice or two? Play chromaticly up or down the keys: If every 8th note fails, or if the dead keys are 8 notes apart,(that is, if two or more notes out of every 8 fail) then you've lost a voice. )or two)
IIRC it uses the CEM 3379 chip.

Agree with rhino. Check to see that it's not a dead voice chip first. If you wind up having to tear the keybed down, I'd break it all the way down to use the Deoxit (but that's just me). Even with the Deoxit, not all the grunge came off. I had severe oxidation. My unit is o-l-d...

[drjay51]

I have checked and there is no pattern to the keys not speaking other than it always involves multiple keys being played at once such as chords. When playing a single melody line or chromatically up the entire keyboard every key sounds. I have also tried various different voices, they all perform the same. I then checked to make sure I wasn't using more than 8 keys at once so I played a series of 6 note chords in progression and some notes would drop out.

I took out the keyboard and and attempted to lightly scrap the tarnish off the key bus wires with some success but of course the brass springs still would still be tarnished. I think that helped but it may be wishful thinking on my part.

The only other cause I can think of would be somehow related to the released keys still sounding. The ESQ1 will hold a released note until it has died out so if the piano voice has a long sustain and you play more notes quickly perhaps it's dropping the new notes? I don't recall it doing that before and this used to be my primary keyboard. I would think I would have noticed this years ago if it was happening then. But then again I may have been paying more attention to the women on the dance floor than my playing? OK, so maybe I wasn't the most dedicated musician in the world, but there were some mighty fine women at those weddings and it doesn't take much concentration to play "Color My World" for the eight thousandth time.

[rakk95]

O.K...based on that latest diagnosis, I would check the height of the nylon key contact spring holders and make sure they're adjusted uniformly.

The keyboard encoder "looks" for two things: contact made at the top (which it reads as "note off") and contact at the bottom ("note on"). The relative time it takes the spring to go from top to bottom is read by the encoder as velocity.

If the spring doesn't break contact at the top because of off-kilter adjustment of the spring holder, the ESQ will still think the key wasn't depressed. Same goes for "note on" if the spring never breaks contact at the bottom of the stroke.

Deoxit will work fairly well to remove some of the grunge, but not all. My springs still look pretty tarnished, but they make good contact and that's all that counts. No points awarded for more current flowing through the diodes - it's either "on" or "off."

Once you get this set up to your satisfaction, I'd then go back and check for all eight voices. If you've still got a problem, we're off to some other trouble-shooting steps. If it winds up being a voice chip, the good news is that they are still available and they are socketed on the PCB, so they're relatively painless to swap out.

DY

[rhino]

Help an old guy remember: What scheme of note-assignment does the ESQ use? On some older synths, if you play one key at a time, the same oscillator is used over and over (on Korg it's called Poly 2). Others use a rotating assignment method. (each new key-press uses the next available oscillator)
Try playing an 8-note broken chord (holding each key while you play the next one) and see if you get the 1-of-8 drop-out.

[rakk95]

Ooo...not sure....I haven't dived that deep into the OS or logic circuits.

I just use trial-and-error and deductive reasoning. Your method would be the one I would use.

DY

[drjay51]

Some great suggestions guys (I assume you are guys, although rakk95 could be suggestive). Anyway I got the deox, was able to apply it with a toothpick and used a dental pick to lightly scrape anything I could see. Definitely cleaned up most of the tarnish so things looked better. Put it back together and it seems to have helped. I also tried the built up chord idea and verified that note number 9 doesn't sound, 1 thru 8 is fine but then that's it. I assume that is the way it's supposed to work. Or is it supposed to steal note number 1 and sound number 9?

I have also verified that the problem is related to any of the voices with long tails or slow decays such as the strings. Playing very legato clearly aggravates the problem with strings. With shorter envelopes the problem seems almost non existent. So I'm beginning to lean towards the spring adjustment idea. So how do you go about adjusting the springs?

Should they all just make contact at the bottom while at rest? Or should they be adjusted to just hit the top bus?

I truly appreciate the advice and help

[rhino]

While at rest they should hit the top buss and bend over it. When the key is pressed, the spring should go down and bend around the lower buss the same (+/-) amount, If you have an early model, there is a tiny white nylon screw at the bottom of each key spring "pusher" Later models, there is no screw...you just have to GENTLY push or pull the nylon spring holder up or down on the key...it has many ratchet-like teeth so you can adjust it.

[drjay51]

I have now checked the spring alignment and everything was OK. I tweeked a couple of the adjustment screws so I would feel like I did something but truthfully they were all making full contact top and bottom. The only thing left that I can think of is that I recently hooked up the midi from my Roland E09. I noticed that every time I selected anything on the Roland the ESQ1 would change something. I have since learned from Roland that the E09 sends everything out so you are supposed to kill the receiving channel on the second keyboard. It doesn't seem likely that any midi signals could have reprogrammed anything on the Ensoniq but I'll reload the system from my rescue tape and see if it makes any difference.

[rhino]

(sound of lightbulb going on...)
If you have both MIDI cables connected between the Roland and the ESQ, check the Roland to make sure it is not set to echo the MIDI in from the Esq...If so, the Esq will be playing TWO notes for each key-press and use up the polyphony (and run out of notes) too fast. Also, the ESQ may not like the Rolands' running-status MIDI signal.

[elsquirrel]

Just a quick question, seeing as you guys seem to know the actual psychical keyboard pretty well. Given I have no other information on the esq for sale other than three keys are not working, what do you think my chances of repair are?