ESQ-1 display stopped working

[Bowe]

I haven’t used my metal ESQ-1 for years because last time I tried it I got no sound out of it, however MIDI OUT worked so I could control a sound module. Now I wanted the next generation, my daughter, to experience this great vintage sound so I installed a new battery and magically the old lady came alive. Victory! For a while… I forgot to turn off the keyboard one night and in the morning the display was dead. I still get sound from it but I can’t change because none of the buttons respond, just the volume slider and the is blank.

I thought the first step is to find out what is broken so I downloaded a service manual and checked the power supply, it’s a EA 001 220 v transformer and the power supply is a 4001004201. I can handle a soldering iron but I need help determining what to do with it

I checked the voltages and some of them were out of range:

Designation Allowed range Reading
Digital supply 13,5 - 16,5 19,1 V
Analog supply 22,5 – 28 29,3 V
Vbb +45 to +55 +59,2 V
According to the service manual the Digital Filament and Filament should read the same but I got 10,0 and 10,9 V

Any help would be greatly appreciated! I grew up with this synthesizer and it would be fantastic if my daughter could use it more than 30 years later. So, does anybody have a hint about what to do?

Thanks in advance and greetings from Sweden!
/Bowe

[Rasputin]

Search for Ensoniq ESQ-1 (about 40% of the way down the page) for suggestions on recapping the PSU:
http://zine.r-massive.com/recapping-cla ... -samplers/

But I don't think the measured voltages are the direct cause of your problems as the voltages that are coming out of the regulators are correct. Well, I am assuming so, as you didn't say you measured anything else that was incorrect. In other words, if you measured +5V digital as about 5VDC and +12 display as about 12VDC and +/-12 analog as about +/-12VDC then the components on the boards themselves are probably seeing the right voltages.

Given that you can still make noise with it then we know the CPU is booting and the mainboard works primarily. We should test the display board separately.

What I would do is disconnect the display board from the mainboard, but NOT the power supply. In other words, there is a 4-wire connector which carries the communication between the display board and the mainboard, and there is also another power connector hooked to the display/keypad board. Leave the power connector hooked up to the display, but unhook the 4-wire communication connector which leads from the mainboard to the display. The end connected to the mainboard is probably the easiest end to undo.

Once you unplug the 4-wire connector, turn the ESQ-1 back on -- you did have the ESQ-1 off when playing around inside it, right?

Now punch some random buttons on the keypad. If the display starts showing weird characters then we know we've got a bad communications issue between the display and the mainboard. If the display does nothing at all and looks totally dead regardless of what or how many keypad buttons you press then there's probably something wrong with the display board.

[blueknob]

The display chip dies, also the same chip does the front panel buttons too, it's a common failure now on the ESQ-1. Only fix is to get the kit from Herr Butchy in Germany. I had this problem about 18 years ago, I was in communication with the guy, sorta working up a fix, he finished it, I got diverted, who cares, he's the man. At the time he had bought last of the Rockwell controller chips and selling them at 50 Euros each, I'd think he's sold out by now but I think he's designed and programmed up a fix.
He also is well known for the mods to the ensoniq SQ80 too. Do a web search, easy to find.

I think there is another thread in here on the same subject, I gave more details there with tech info. Just buy the fix kit!

[Bowe]

Search for Ensoniq ESQ-1 (about 40% of the way down the page) for suggestions on recapping the PSU:
http://r-massive.cellarseer.com/recappi ... -samplers/

But I don't think the measured voltages are the direct cause of your problems as the voltages that are coming out of the regulators are correct. Well, I am assuming so, as you didn't say you measured anything else that was incorrect. In other words, if you measured +5V digital as about 5VDC and +12 display as about 12VDC and +/-12 analog as about +/-12VDC then the components on the boards themselves are probably seeing the right voltages.

Given that you can still make noise with it then we know the CPU is booting and the mainboard works primarily. We should test the display board separately.

What I would do is disconnect the display board from the mainboard, but NOT the power supply. In other words, there is a 4-wire connector which carries the communication between the display board and the mainboard, and there is also another power connector hooked to the display/keypad board. Leave the power connector hooked up to the display, but unhook the 4-wire communication connector which leads from the mainboard to the display. The end connected to the mainboard is probably the easiest end to undo.

Once you unplug the 4-wire connector, turn the ESQ-1 back on -- you did have the ESQ-1 off when playing around inside it, right?

Now punch some random buttons on the keypad. If the display starts showing weird characters then we know we've got a bad communications issue between the display and the mainboard. If the display does nothing at all and looks totally dead regardless of what or how many keypad buttons you press then there's probably something wrong with the display board.

Yes, I did turn off the ESQ- before poking around But unfortunately there was no sign of life on the display I guess I will have to give up the easy fixes and go for the hard and more expensive ones. Anyway, thanks for your help!

[Bowe]

The display chip dies, also the same chip does the front panel buttons too, it's a common failure now on the ESQ-1. Only fix is to get the kit from Herr Butchy in Germany. I had this problem about 18 years ago, I was in communication with the guy, sorta working up a fix, he finished it, I got diverted, who cares, he's the man. At the time he had bought last of the Rockwell controller chips and selling them at 50 Euros each, I'd think he's sold out by now but I think he's designed and programmed up a fix.
He also is well known for the mods to the ensoniq SQ80 too. Do a web search, easy to find.

I think there is another thread in here on the same subject, I gave more details there with tech info. Just buy the fix kit!

If I did my googling correct it would be something Butchy calls BMD65003 "Display/Panel Controller Kit
functionally compatible with 1380-65003 contains processor, adapter PCB, and sockets/pin headers". Does that sound like what I need? Costs 49 Euro and that seems reasonable to wake up this beauty from her sleep. Only thing that concerns me is the part "Assembly required"... I guess I will have to contact Butchy and give it a try. Thanks for your help!

[blueknob]

Yes that sounds like the one, I'd have to go double check all the part numbers but Herr Butchy is the man. The exisiting 40 pin DIL controller chip needs to be removed, it does take some good soldering skills, it is very easy to damage the PCB. I'm sure then the kit will be a easy fit. At 49 Euro, just buy one! as there is no other way to fix these failing chip problems. At the time when I had this problem my ESQ1 cost me £100 so 49E was almost half the cost of the synth!

Not everyone has the soldering skills for the job, or even fancy the job, however if I recall correctly, it's an easy job to dismantle the display boards, then the PCB with the VFD display and the faulty chip can be simply unplugged so you could send them to a good local tech and they do the soldering job for you.

[Bowe]

Yes that sounds like the one, I'd have to go double check all the part numbers but Herr Butchy is the man. The exisiting 40 pin DIL controller chip needs to be removed, it does take some good soldering skills, it is very easy to damage the PCB. I'm sure then the kit will be a easy fit. At 49 Euro, just buy one! as there is no other way to fix these failing chip problems. At the time when I had this problem my ESQ1 cost me £100 so 49E was almost half the cost of the synth!

Not everyone has the soldering skills for the job, or even fancy the job, however if I recall correctly, it's an easy job to dismantle the display boards, then the PCB with the VFD display and the faulty chip can be simply unplugged so you could send them to a good local tech and they do the soldering job for you.

Sounds great! I mailed Buchty and 49 Euro is reasonable since there is no ESQ-1 for sale in Sweden. I really like the sound and the sequencer in the ESQ-1 so it's definitely worth a try. I haven't soldered a DIL the last 30 years so let's see how brave I feel. Keep your fingers crossed and thanks for your help!

[AndrePolo]

my synthesizer also worked badly, the left speaker worked quietly at all, right half of the power. I had to change the entire board to get rid of the problem. Can you also do?

[Synthtech]

I have two ESQ-1's here and they both had the black screen problem. I just went through testing the power supplies for both of them and they had the same issue. The middle JE172 transistors on both power supplies tested bad. I just put in an order for some replacements. I'll post an update when I get them installed.