Rodgers 702 not working

[Dr Z]

There is a slight possibility that I may be coming upon a good deal on a Rodgers 702 and the accompanying PR300S. The organ was new about 15 years ago (when I played at this church) and was a wonderful replacement for the Baldwin predecessor. Sadly, it has only been played a few times in the past 5 years. I was recently told that the organ is not working. Also, the church is no longer interested in using the organ and they would like to utilize the organ niche for something else. Therefore it is unlikely that they will have it serviced - either for diagnostics or repair. A friend is on the Property and Space committee which will meet next week. He will try to find out the scoop as well as tell them that I'm interested in getting the organ - assuming that they don't want much for it and there's a good chance that I can get it playing for not much $$.

I plan to visit the organ within the next few weeks and will take along some headphones (speakers have been disconnected). Does anyone have any suggestions on how I might do some basic diagnostics?

1. Assuming that the organ powers up, lights come on, lighted stops turn on/off when pressed, pistons cause registrations to change might it be safe to assume that the problem lies in the sound-producing portion or amplifier?

2. If it will play through the headphones, I'm thinking that the pre-amp is fine and the problem might be the main amplifier. I had a Yamaha Clavinova that quit after a lightning strike. All fuses I could find inside looked fine. Decided to try the headphone jack and it played, so I gave it away to a beginner. According to the 702 Owner's Manual I found online, there are L/R output jacks next to the headphone jack, so might I be able to connect it to a home stereo which should be satisfactory for basic practice?

3. Somewhat unrelated question that should probably be posted in another thread: eventually, I would hope to interface it to my pipe organ control system to play my 13 ranks of pipes once I gather the energy to get the wind chests set back up. Is it difficult to tap into the key and stop switching? I would let the organ's own computer handle the pistons. This question might be important if I can't get sound via headphones.

Thank you,
Keith in Athens, GA.

[jbird604]

Keith,

I replied to your post about the MIDI on a 702, though I had to admit that I was not fully up to speed on that subject. However, having seen and serviced a 702 and many other models of the same series (sometimes called "Cheetah" organs), I can tell you a few things to look at before you commit to this organ.

#1 - keys. These organs used a keyboard built by Roland which was later found to have a fatal flaw. A pinkish epoxy was used to glue the metal weights up inside the hollow plastic keys, and that glue can fail over time, turning into a thick goo that slowly oozes out of the keys, letting the key weights fall out. The first symptom may be sticking keys. The weights come out still coated with enough of the goo to cling tightly to whatever they land on, and the oozing goo will get all over the piston rail and other parts. In short, it is a horrible mess and ruins the organ.

For many years, Rodgers provided a replacement key action, but the supply of those has long been exhausted. AFAIK, they cannot be bought anywhere at any price. Some techs claim to have fixed them by soaking the keys in lye to remove all the epoxy, but I have not done this myself. At any rate, take a look underneath the keys and see if the pink goo is oozing out. If it is, that's much cause for pause.

#2 - exploding capacitors. Many Rodgers models built during that era contained at least a few of the infamous silvery-blue 1000 mfd capacitors in one or more power supplies, or as final filter caps on certain boards, such as the four-channel pre-amp which is the audio processor in this model. These infamous caps were from a flawed batch of parts that were used over a period of years before the trouble was found. These caps tend to leak corrosive juice onto the circuit boards, and will sometimes catch fire and explode, making a cloud of stinky smoke and sometimes damaging the circuit board. To my knowledge, none have caused an actual fire in a building, because the fuel involved is very small. But they will of course disable the organ and require a repair that may be expensive.

So......... look at the keys for the pink goo, and check the four-channel pre-amp board to see if it still has the silvery blue 1000 mfd caps. Either or both problems MAY have already been caught by a tech and taken care of long ago. Or maybe not.

Beyond those issues, these organs have been quite durable and have a fantastic feature set and a great sound. You should look at the speakers. Some of them could have rotted foam surrounds on the woofer cones, but that is not nearly as big a problem, quite simple and cheap to fix.

[Dr Z]

John,
Thank you for your reply. I don't think the organ has ever been serviced. A friend and I reconnected the speakers after we moved their locations. I remember at the bottom of the rear section there being two pairs of connectors - L/R Bass and L/R Treble. Also were knobs (I forget how many) to set the overall volume of the organ as well as to balance the Great and Swell to the sides. I sent the Great mostly to right and Swell mostly to left. That's all I remember from being inside the back of the console.

1. So, from your description, I should look and feel over the underside of the overhanging portion of the key? If things are looking OK, I'm wondering if there's something I can do to prevent this problem from happening.

2. Relative to where I would have connected the speakers, can you tell me where to look for these capacitors?

I'm thinking that my first test will be to try headphones. If no sound comes, then I should probably pass on this. I already have 2 consoles that are OK for my pipe organ project. I was hoping that this would give me a currently functioning digital that I could practice until I get the pipes set up.

Thanks,
Keith

[jbird604]

You'll have to discern the condition of the keys. If they are not dripping glue, they probably don't have the bad epoxy, so you'd be ok. The four channel preamp board is the one with a set of 12 thumb pots, 4 orange to set levels of the four channels, 4 treble (yellow) and 4 bass (red). They are near the right edge as you look at the board from the rear.

[baldwinc630]

Another thing that you can do is to look to see if there is a pipe interface in the organ. Some 602/702 organs had them provided just in case. If this organ has one, you may be in business. B630

- - - Updated - - -

I almost forgot. The keyboards, if they are not oozing out the glue, should be ok if not exposed to extreme temperatures. Also, on the audio side. This particular organ uses the STK-4192 stereo amplifier chip in its audio output modules. On some Rodgers organs, they are known to go bad by blowing the fuses on the module itself. Also, As JBird604 indicated, the audio pre-amp boards also go bad on occasion. I've had to replace both of these on a 580 which has a similar layout. Hope this will help. B630

[Dr Z]

Thank you. I'll have to check on the pipe interface. I was pianist/organist at this church when the organ was purchased and even connected the speaker wires when the speakers were relocated.

I haven't heard from my friend on the property and space committee of the church. If they decide to let me take it for a very low price, it might be worth it to pay a service person to check it out for me so I can find out exactly what's wrong and how much it will cost to repair it. The primary advantage of this particular organ is the hope that it will play in some capacity as a digital organ in order to let me practice regularly while I get my pipes set back up. Also, insofar as my MIDI question in another thread goes, Give me circuitry to tap into (MIDI or not) to connect to my Opus-II control system.

Thanks again.

[Dr Z]

Update on the Rogers 702: I visited the organ today. I took along headphones and a screwdriver.
- My friend on the Property and Space committee told me that there had been a lightning strike and the organ and a flat screen monitor on the wall above the organ went out.
- He also said that the speakers were bad. Someone who knows about these things checked them out. There were 2 pairs of speakers, with 1 pair in each of two chambers on either side of the choir loft. Each pair consisted of a bass and treble. Don't know how all 4 went bad.
- The church doesn't have a price. I don't think they're interested in paying for a diagnostic service call. So, I should find out in a few weeks what they want.

Now my observations:
1. After I located the detached power cord and figured out where to plug it, and turned it on, everything lit up as it's supposed to do. Stops lit and pistons worked.
2. After fiddling with the headphone jack, I got sound thru the headphones. The stops worked fine. Very likely, many of the pistons are as I left them 12 years ago. The volume responded to the swell pedals.
3. There was no sound externally, which makes sense if the speakers are gone and the chambers boarded up.
4. There were 5-6 stuck keys which came loose after a press or two.
5. Every key played except one sharp on the Great. It was not stuck; it wouldn't play. I noted that it did not depress quite as far as the others.
6. I looked carefully at the 4 speaker wires coming from the back. Each looked just like brown 2-conductor extension cord wire. I'm thinking that this makes it less likely that the organ used powered speakers. As I remember during the 1st Sunday the organ was there, the speakers were sitting on the platform and had no power cords connecting them to electrical outlets.
7. This makes me think that the organ contains an amplifier, not just a pre-amp. There was no way to connect external speakers to it today, so I couldn't test that.
8. My greatest curiosity was satisfied when the organ sounded fine thru the headphones. Therefore, I didn't take the time to open the back of the console.
9. I'm wondering that what happened is the same that happened to a Clavinova of mine years ago after a lightning strike. I'm hoping that the amplifier might have been the only thing damaged. I'm assuming that headphones come off the pre-amp.
10. I got a quote from the Rogers service person for my area. If it is only a bad amplifier, I'm wondering how much a replacement costs and if that is something I could replace myself.
11. Since the headphone jack works, I could run a stereo plug from the phone jack to the microphone jack of a stereo receiver and play it thru a stereo.

I'd appreciate any observations you might have.
Thanks,
Keith
Athens, GA

[jbird604]

The few sticky keys probably indicate a mild case of pink glue syndrome. Might or might not progress to a serious issue. The speakers all had foam surrounds in the woofers, so that may be why the were all declared "bad."

The amps are modular plug-in boards, which are used in large numbers if Rodgers models, so they should be available. Could be a little pricey though. You could get by using the stereo outputs into a good quality sound system. Would be preferable to use four good speakers and maintain the intended four channel configuration. The amps may in fact be fine, or only need fuses.

I don't think the church should expect to get much of anything for this organ, given that it currently isn't even playing, and has obvious problems. They certainly won't get any takers other than hobbyists willing to take it on as a project.

[Dr Z]

The few sticky keys probably indicate a mild case of pink glue syndrome. Might or might not progress to a serious issue.

Thank you. Where in the keys are these weights that have the glue in them? Would this area be accessible by removing the stop rail? I don't guess the keyboards slide out like the one in my Steinway.

If I get this, I will very likely connect it to a stereo. I don't think I'd be able to maintain the 4-channel configuration accessing from the front (1) the stereo headphone jack or (2) the L and R audio output jacks on the panel above the knee board. I would need to tap into the output of the pre-amp (or at the point where the pre-amp connects to the amp.

I found this at Best Buy:
https://www.bestbuy.com/site/pyle-30...?skuId=4505606

Thanks,
Keith

[jbird604]

Very difficult to disassemble this model. Totally unlike the fairly simple and easy to access keyboards of the higher end Rodgers organs, and most other organs you'll see. All manner of screws and nuts and wires to disconnect. It's a nightmare. Was not put together with the idea that it would ever need to be opened up.

You can remove the two piston rails by taking out the four very small screws in the front of each one, then you can see under the keys with a flashlight. You might be able to reach under with a sharp pointed tool or wire and dig out a lump of goo, if that's what is wrong the one key that doesn't go down all the way. Or maybe not, depending on how far back in there it is.

The pink stuff can often be seen oozing out under the fronts of the white keys, but in some versions the white keys are sealed on the bottom, and the only oozing is from the underneath of the sharp keys, which isn't as likely to totally kill the organ, but will make you need some annoying service and maintenance from time to time, unless you figure out how to get the stuff cleaned out when it drips.

Best I recall, to take out the keyboards for service, you must first take off the back of the console, then remove the top, which is held down at the rear with screws going up through a stretcher rail. Then you take out the roll top, then remove the stop rail, which is held in place by an assorted mess of L-brackets and such here and there. Watch out for the dangling wires and cables. Once all that is out of the way, the keyboard stack can be detached from the console by taking out some screws in the bottom of the keydesk. Remove the cover from the digital generator assembly, if it has one, and unplug the keyboard cables from their flimsy sockets, being sure to mark them and take pics so you'll remember how to put them back in place.

With all that done, you should be able to lift the keyboard stack out. Then you have to take it apart by removing a gaggle of screws and brackets and stuff that joins the upper and lower manuals.

Once separated, you can remove individual keys by carefully loosening the spring from the rear of the key and the metal "comb" bracket, then lifting the key up out of its channel. Lift the rear end first, as the front is captive in a guide pin. Once out, you can remove the sticky blobs of glue from the bottom, and clean up the felt bumper strips under the keys.

Then you have to carefully, methodically re-assemble everything.

Then pay yourself about $500, because a tech would charge that much and will earn every penny of it!

As to the audio, first try connecting good speakers to the four speaker wires left hanging out the back. They just might work. If not, look at the two amplifier modules (on the far left of the shelf, as you look in from the rear). See if any of the fuses are blown. If all else fails, you can certainly connect to a stereo amp using the line outs on the front of the console. That Pyle amp you linked to has pretty bad review, and if it's like some other Pyle electronics I've seen, it could be pretty poorly designed. But then it might be fine as an organ amp. Most of the complaints in the reviews relate to the bad remote control, the ill-designed radio receiver function, and the way the volume always defaults to very loud when the amp is turned on. These might not be of concern in a fixed-level usage such as for an organ amp.

Good luck! I really hope you don't have to actually take the keyboards out. It truly is not for the faint of heart!

[Dr Z]

Jbird604,

Gee, it wore me out just reading that. So it's not going to slide out onto my lap like my Steinway?!?!? During high school, I completely dismantled an old tall upright piano and refinished it. When I finished reassembling it, there were a couple rather large screws remaining. No telling where they were supposed to go.

As soon as I posted the link for that receiver, I saw the reviews. For me to practice it in my basement, connecting it to a stereo receiver should work well.

The fronts of the keys are sealed; I felt nothing sticky, and I saw nothing pink. I should visit again, remove the piston rail as you said and take a peek under the F# that won't depress all the way.

It's likely going to be a tough decision. I have a 1950s Austin console that I used to play my pipes, but it's filthy and ivories are . A friend gave me an old Allen console that doesn't play, but whose keying had been tapped into to play his pipes.

The perceived advantage of this Rodgers is that, if it can play thru headphones or a stereo, it will provide me an instrument on which to practice while I get my pipes reassembled. It is also hoped that this console can be connected to my pipe organ relay system.

Thanks,
Keith

[jbird604]

You know, Keith, it is remotely possible that the key stack might actually slide out the front if you get it completely free of all the insides and remove the four long screws that go up through the keydesk into the end blocks. I seem to remember seeing another tech do that once. The Cheetah organs were not all alike though, as Roland provided Rodgers with more than one style of key action during that time period. Some might be easier to remove than others. Still say that these organs were never intended to be taken apart for servicing!

[Dr Z]

jbird604,
I e-mailed the Rodgers technician for our area and told him what you said regarding the key stack. I told him that I wasn't asking for free advice, simply a ballpark estimate for replacing an amplifier and fixing a stuck key. That way I'll have an idea what I'm getting myself into. I had already received a quote from him to do diagnostics. Also, it gives me something to tell the church insofar as how much the organ may be worth. They said they want to use the organ niche for something else, so I think they're motivated to get rid of it. Meanwhile, I may re-visit the organ and remove the piston rail and look as you suggested.
Thanks,
Keith

[jbird604]

Good plan. Let me know what happens.

[Dr Z]

Thank you for your help thus far. Here's an update after visiting the organ a 2nd time. I tried to embed photos and couldn't figure it out.

I took along a pair of Bose 201 Series III bookshelf speakers rated 10-120w/c and 8 ohms.

1. There is, in fact, glue under several of the keys as shown in the photo.
2. I removed the piston rail from the Great to try to figure out why the F# hits a hard stop before it's down all the way and won't sound. I couldn't see it well enough.
3. For my test of the external speakers, I connected the speakers as follows, since I only had 1 pair.

• Channel 1 & 2: Swell sounded great. Great wouldn't sound at first. As I depressed the Great expression pedal, the Great could be heard softly and sounded ethereal sort of like reverb.
• Channel 3 & 4: Great sounded great. Swell was very soft and distant as described for Great above.
• I had moved the pedalboard out of the way, so I didn't get a chance to see where it played in the scheme of things.

4. From the photo showing the channel assignment: it appears that connecting a pair of speakers to Channels 1 & 2 are the correct way to wire it as a 2-channel sound. But ... the Great was almost inaudible when tested this way. Perhaps there is something that is configured to indicate that you're setting it up as either 2-channel or 4-channel. If I had had 4 speakers with me, it probably would have sounded great.

As I was testing, my non-musical friends asked, "so probably it was not struck by lightning?" All I could tell him was that I don't know enough to determine that it isn't damaged.

5. I was expecting to only be able to depress the expression pedals a tiny bit since the sound would easily fill the 200 capacity sanctuary. I don't think we had powered speakers attached originally. Anyway, the sound was quite comfortable coming thru the bookshelf speakers. I'm not sure what this means. If the amp is blown, is it possible for enough current to pass thru from the preamp to power smaller speakers?

I'm still very confused. I can't imagine any other console I would have wired speakers to, but the connections looked much different from what I remember. I remember there being some knobs - I think each manual had treble and bass knobs. There were also balance controls. I remember setting Great to go 75% to right and 25% to left and Swell was just the opposite. I didn't see any of those controls today. In fact, I didn't see anything that could be adjusted by fingers. I did not see anything labeled Pipe Controller.

6. My friend told me that the property committee plans to suggest to the church that they let me have the organ for $500. I'm thinking long-term. The main advantage of the Rodgers is that it would give me a digital organ that actually plays so I can practice while I get the pipes set up.
- The glue problem is very concerning if I want this console to be a long term solution.
- It's obvious that I'm going to have to tear it down to get access to the stuck F#. The technician told me that the last time they replaced keyboards in this style of console, it was $4500!!!

So . . . I would certainly appreciate hearing the collective wisdom of the group on all this.
Thanks,
Keith