Unlocking the Yamaha E70

[Alejandro]

Hello Ewaves,
Hope you solve it soon.
I am presenting pieces to make calculations ... disassembling the CSY to leave only the synth part has been crazy, I thank Marc Brassé who has sent me photos and has given me advice. I hope to get it all together without any explosions. A greeting!

[Alejandro]

E-70

[Alejandro]

Csy2

[Ewaves]

Looks very solid, if you have some soldering experience and follow his advice, I think you can manage it, be patiënt and secure.

[Alejandro]

[Alejandro]

[Alejandro]

[Golfbidder]

YAMAHA Electone EL70 ORGAN

PLEASE CAN ANYONE HELP ME WITH A FACTORY RESET PRECEDURE, JUST GET A ALL MAINS HUM, NONE OF THE 8 PISTONS
WORK ALSO YAMAHA EL70 PRE RECORDED DISCS EVEN THOUGH THE DISPLAY SHOWS THEY ARE BEING READ? PERHAPS IF NO FACTORY PRESENT KNOW. PLEASE CONTACT ME ON trrydvy@yahoo.co.uk WOULD BE ONLY TO PLEASED TO HEAR FROM YOU.

[Ewaves]

@Golfbidder

You are in the wrong thread, this is for the E70, but reading your question, I guess you have a power supply problem, check the voltage's.

[Alejandro]

Hello Ewaves and other users, I am already handling the parameters of the modifications! now I have to learn how to handle filters well. It is more work than it seems, on top of this the multi-effects will go and something else, then everything will be closed with the original cover ... A greeting.

[Ewaves]

Hello Alejandro

Yes, just take your time for it, if you make a mistake, a lot of parts are not available anymore.
I also started, first testing the power supply, have no capacitor tester, but it's look good, a ripple of about 1V peak to peak on the unregulated supply its not bad, I think, no deforming on the capacitors, looks good.
But when the organ was build, the main voltage was 220V AC, but over the years it became 230V AC, so I put the two switches on 240V, give a little less stress to the regulated power supply, no adjustment's needed for the outputs.

I also noticed, that the decoupled electrolytic capacitors all over the boards are very close rated to the working voltage's, 6.3V to 5V and 16V to 15V !!
Well, time have proven that it will be okay, but if I have to replace some, I will take 10V for 5V and 20V for 15V, just to be sure.

The other thing I notice, I say before E50 is the same as E70, and there is some space on the pcb's to put some missing components there, but the Digital pcb's enclosure have a different
motherboard, no space to put some missing cards in it, so it's not possible to make from a E50 a E70 out of the box.
Another downside is, that there is nearly room to make measurements on the digital cards, you have to make an adapter cable with some extra connectors, and the connectors are made by Yamaha, so I think its not an industrial standard, have to dive in that.

[Ewaves]

Sorry, I totally messed up with the picture upload, so will continuing here;

Digital box with uncommon connectors and very less space between the pcb's

And for now I try to repair the hanging lower keyboard, stuck on 4', the CD 4071 on this pcb is the suspect....


Greetings.

[Alejandro]

Hi Ewaves,

I will have to look at the values of my source, and surely change capacitors. Glad to see you are doing things on the E50. Yesterday I did an experiment adding sensitivity - aftertouch to the "Upper" keyboard by means of a lever mechanism and a photoelectric cell, interesting things can always be done in a paraphonic way.

A greeting.

- Alejandro.

[Ewaves]

Lower keyboard repaired.

[Alejandro]

Hi Ewaves, I'm glad you fixed that fault! what is the next step you are going to take? Greetings