Bringing an Electone D85 back to life

[Jorgino]

Hi all,

In complement to my other question about my D85. The only thing that works are the levers (flute, strings, etc.) for UK, LK, PK, and 6 out of 16 rhythms (normal and variation 3 only - none of the break variations work, when you press the green button, it turns on but the organ plays a march pattern - the regular march rhythm does not work). The auto-arpeggio and rhythm chords functions work only when the rhythm is turned on, but it does not change pattern when you press the buttons. 8 keys on the upper manual are intermittent, you have to press either hard or hit it repeatedly to make a sound.
Sometimes the levers for the upper manual quit making sound and I have to play with the combi levers turning them on and off, which seems to "wake up" the sound. Nothing else works, no solo keyboard, no special preset, no custom preset. Yesterday I opened up the organ and disconnected and reconnected all connectors that I could reach and when I turned on the "Solo to Upper" coupler, I was able to play solo sounds for like 5 secs (on both solo and upper keyboard) and then it stopped. I noticed that when I turn the volume to the max and press a key, even with all sounds turned off, I can hear the notes I'm playing, very faintly and some kind of noise (like when you put a cell phone close to a speaker), then 3-5 secs after I release the key, this noise also becomes very faint, it's like there's a noise suppressor circuit, but I'm wondering if there's a "mixing" circuit and it has an issue and therefore I cannot hear solo, preset and custom sounds. I have the possibility of purchasing another D85, everything on it works except the rhythm box, it doesn't even display the tempo, everything is off, so I'm thinking it might be a power issue. What's the intelligent course of action, purchase this other unit and try to fix just the rhythm box or tackle my current organ with the myriad of problems it has (unfortunately when I acquired it, they told me the only thing not working was the solo keyboard)? I'm pretty handy with things but no electronic expert. I have a multimeter, soldering iron and need to fix my oscilloscope. For you experienced folks, what's the methodology here? Where should I start? I'd hate to start unsoldering capacitors only to find out I'm tackling the problem from the wrong angle. I'm not expecting anyone to tell me what's wrong just based on this description but if you could give me some pointers? I'd have to pick up the "new" organ this week if that's the best approach. Please help a brother out. Thanks!

[Larason2]

This may be a fool's errand. Once you get to the D85 in 1980, the tone generation is full of proprietary IC's that are no longer obtainable. I suppose between the two of them you may have one full set of IC's, but I would progress with the knowledge that even with two of them complete repair may be impossible. Most of your problems make it sound like the tone generation boards are at least partly at fault. You may actually need three of them, with the third one having at least the rhythm functioning.

As for the methodology, repair starts with the power supply. Open it up and check the voltages and make sure there's no AC ripple. Even if it checks out though, given the age and the extent of the problems, you may still want to replace all the capacitors, especially given that your IC's are unobtanium. Once that is done, you also want to make sure your amplifier and drivers are in good shape, which can be done separately from the tone generation. Then, I would pull out all the chips, clean their contacts and the switches with deoxit, and all the slide potentiometers with fader lube. Really, once you finish that, you want to hope that it works, because there's not much else to do in the tone generation. For any given problem with the tone generation, you'll have to track down which IC is at fault, and replace it with one from your donor organ, then hope it works. If it still doesn't, you have to keep exchanging chips. If you reach a point that you have a chip where you don't have a good copy, you can ask around to see if anyone has it online, or as I said look for a second donor organ. If they don't, you can try replicating the chip with an Arduino. That's going to be a lot of work though! For all this, having the schematic would be helpful, you can ask for it on the relevant portion of the forum. Given the complexity of troubleshooting once you get to the tone generation, it may actually save you time and be better to use your donor organ as the "good" organ, and use the current organ for parts.

It's a shame, because the D85 was a good organ. Personally, I would gut it, convert it into a midi controller, and call it a day.

[Jorgino]

Thank you for your feedback, I'll definitely take a closer look at the capacitors in the power supply, there are some huge ones that I'm assuming cost a pretty penny, especially post-covid. But since the power supply is working, this is more of a preventative measure than restoring functionality. I also am interested in getting rid of all tantalum capacitors as those have the tendency of putting on quite a show when they bid farewell.

Personally, I would gut it, convert it into a midi controller, and call it a day.

Not really a thing for me, I actually have midi controllers and other Electones with MIDI capability if that was the case. I'm really interested in restoring the D85.

[Larason2]

Ah, fair enough. Actually those big capacitors were multi value ones that aren't really obtainable anymore either. Usually we recommend getting multiple modern caps that will cover the same values. Sometimes they are all small enough to fit in the same canister. Ideally 105c, long life caps, from a reliable maker. I still wouldn't pay more than $2-5 each though. If you can't find the right values, usually going up a bit on the voltage or capacitance is ok.

Also, just because the power supply is working doesn't mean it's not the problem. IC's in particular are very sensitive to overcurrent, even if it's mild. Many organ related problems on this forum have been corrected by replacing power supply caps. If you don't want to replace them all, you can potentially get an ESR meter, or use a scope and a signal generator to test the ESR. It might not be worth the money if you don't have them already though!

[tucsondave]

Do you know if this organ sat unused or in storage? Your description sounds like you have major switch problems.
I would start with checking the voltages at the power supply. If okay then a close visual of the interior checking the presence of rodents. Next I would apply deoxit D5 to every pushbutton switch and make sure every switch does something. You didn't mention which rhythm switches work. Knowing this is important since there are parallel to serial IC's involved.
If the other D85 is reasonably priced that might be the best way to go.

td

[Jorgino]

Just ordered a new can of DeoxIT D5 and F5, keeping my fingers crossed!!

[Jorgino]

Do you know if this organ sat unused or in storage?

Not sure on that. When I picked up the organ it was inside of the person's home but he's a drummer who was going to learn how to play keys and never did.

You didn't mention which rhythm switches work.

Rhumba, Mambo, Samba, Latin Rock, 16 Beat, Jazz Rock - NORMAL and 3.
Another funny tad bit of information is that the other rhythms make no sound but the counter keeps going up and when I press Waltz, it counts 4 beats instead of 3.

[tucsondave]

That looks like a switch problem to me since those working switches use all three par-ser converters.
I would concentrate on cleaning those switches to see if there is any improvement.

td

[Jorgino]

This may be a fool's errand. Once you get to the D85 in 1980, the tone generation is full of proprietary IC's that are no longer obtainable. I suppose between the two of them you may have one full set of IC's, but I would progress with the knowledge that even with two of them complete repair may be impossible. Most of your problems make it sound like the tone generation boards are at least partly at fault. You may actually need three of them, with the third one having at least the rhythm functioning.

As for the methodology, repair starts with the power supply. Open it up and check the voltages and make sure there's no AC ripple. Even if it checks out though, given the age and the extent of the problems, you may still want to replace all the capacitors, especially given that your IC's are unobtanium. Once that is done, you also want to make sure your amplifier and drivers are in good shape, which can be done separately from the tone generation. Then, I would pull out all the chips, clean their contacts and the switches with deoxit, and all the slide potentiometers with fader lube. Really, once you finish that, you want to hope that it works, because there's not much else to do in the tone generation. For any given problem with the tone generation, you'll have to track down which IC is at fault, and replace it with one from your donor organ, then hope it works. If it still doesn't, you have to keep exchanging chips. If you reach a point that you have a chip where you don't have a good copy, you can ask around to see if anyone has it online, or as I said look for a second donor organ. If they don't, you can try replicating the chip with an Arduino. That's going to be a lot of work though! For all this, having the schematic would be helpful, you can ask for it on the relevant portion of the forum. Given the complexity of troubleshooting once you get to the tone generation, it may actually save you time and be better to use your donor organ as the "good" organ, and use the current organ for parts.

It's a shame, because the D85 was a good organ. Personally, I would gut it, convert it into a midi controller, and call it a day.

Do you have a recommendation for a good ESR meter? I have an analog o'scope but I need to replace the capacitors on it. I might buy a cheap digital just to get this job done, I have a few other electronic projects including a Hammond A100 that I've been procrastinating, maybe this will get my going.

[Larason2]

If you think you'll be checking quite a few capacitors over the long term, an ESR meter makes sense. Otherwise it's pretty expensive! You can get fairly cheap ones from China, but the instructions for using them are pretty confusing. Here’s one that’s come up as a recommended one in my searching:

https://canada.newark.com/peak/72-12...oss_price=true

There are tricks for checking the same thing with a scope and signal generator, but it might not work with older scopes. You can google “ESR oscilloscope”, then take a look at some of the articles that explain how to do it. If you’re able to set your scope to the parameters they recommend, you should be able to use it. The ESR meter is way easier though! You can find charts online of expected ESR’s for various capacitor values.

As Tucson Dave says though, start with cleaning the switches. You may be amazed at the improvement that alone will make!

[Eddy67716]

Rhumba, Mambo, Samba, Latin Rock, 16 Beat, Jazz Rock - NORMAL and 3..

All the rhythms that work are stated to be in group C in my E45 manual (The E45 has similar internals to the D85 except no solo manual). (Group A is swing, group B is waltz and group C is straight.) I don't know if each group is using one of the Rhythm Generator ICs (there are 3 in the E45)

The other thing that could be preventing the rhythms from working is seized up buttons. try cleaning them out or pressing them a few times.

Make sure to replace the Snubbers, at this age they are really bad. They failed in my E45 and took out the Tremolo chip (IG03260). In the E75, they nearly failed and the tremolo chip was stalling, but I replaced them in time. If they go, I think the tremolo chip goes. They protect against surges and instants drops like turning the organ off.

Those 8 keys will need a clean out of the contacts.

Check the voltage regulators are at the right levels to supply the Rack DC circuits.

[Jorgino]

Make sure to replace the Snubbers, at this age they are really bad. They failed in my E45 and took out the Tremolo chip (IG03260).

I did a quick google search and I think you're referring to capacitors when you say 'snubbers', which ones should I be looking at? This thing has literally thousands of these things everywhere.

[Eddy67716]

I did a quick google search and I think you're referring to capacitors when you say 'snubbers', which ones should I be looking at? This thing has literally thousands of these things everywhere.

The paper capacitors in the power supply. If it's like my E45 it will take two 0.068 or 0.047 uF capacitors and one at 0.022 uF (unless you live in the US or Canada), the 0.022 one seems to be a 0.033 uF capacitor with a resistor.

[Jorgino]

oh ok, you mean PSU only. I'll def. check them. Thanks!

[Eddy67716]

Any luck with the organ or did you give up?