Rodgers 750BI - we got it free - but has some problems.

[davidb]

Hi, so we just picked up this organ. Owner was selling their house, was out of state already, and wanted it given to a good home. We were fortunate to obtain it for our small church. Aside from some minor finish issues (the very top layer of finish is peeling a tiny bit), the organ cabinet is in excellent condition. All of the moving stop tabs appear to work perfectly. It does not have the toe pistons (apparently that must have been an option?) There are a few electronic issues, however.

I am not an organ repair person, nor am I an organist (my wife is!), but I have mucked about with electronic stuff quite a bit. I figured I'd try some basic troubleshooting first (mouse-chewed wires, fuses, other obvious stuff, etc.), and then call in an expert if needed. Serial number is 51188.

The issues:
1) One stop is ALWAYS "on". Sounds like an 8' principal (to my untrained ear, that is). What I mean is: with all the tabs turned off, and if one presses a key on either keyboard OR the pedal board, the keys play a single stop.
2) The great manual only plays the swell stops. Like it's a clone of the swell. For example, if I flip on the 8' Oboe on the swell, it plays on the great. And NONE of the tabs on the great affect anything - they do not play on the great manual.
3) One of the memory thumb pistons is broken. I am able to turn it on by closing the circuit manually with a jumper, so it appears to work. I see that replacements can be had from Syndyne.

Aside from these (major?) issues, it plays and sounds beautiful.

Any help would be appreciated!

Thanks,

David

[davidb]

Update:
Issue #1 was due to me not understanding what the "crescendo" pedal does. From under-use, it was a little sticky; once I worked it up and down a few times, and pushed it all the way down, the mysterious "stop" went away.
Issue #2: same cause as #1.
Issue #3: Planning on ordering one from Syndyne. If someone has a better suggestion, please let me know.

One more question: are there any kits to replace the rechargeable batteries for the memory system? Mine are not leaking, but I understand that this is a possibility and causes problems.

Also - can I grease or oil the volume pedal mechanism?

Thanks...

[indianajo]

If you can read the number on the batteries, one of the few things Radio Shack does well is sell batteries. If it is a more exotic number, I have bought a couple of things from batteries.com and was satisfied with the service, although the $6-10 shipping is a bit of an inhibitor.
Drip Oil on steel or other metal on volume pedal is fine. Oil on any potentiometers, light bulbs , photocells or contacts is bad, so don't spray penetrating oil in there until you look in there to make sure none of those are there. I have a squeeze bottle with a long spout from mcmaster.com I use for putting oil in just the right place.
Pots you can lube with "fader lube" which in its previous incarnation was known as tuner lube.

[davidb]

Thanks, Indianajo.

And another thing...got it all back together and discovered that some of the foot pedals do NOT play 16' stops. And none of the pedals play 2' stops.

:-(

Any guidance would be appreciated.

[NoTalent]

If some of the pedals do not work completely, make sure that the pedalboard is locked to the console. If you pull the pedalboard back, you'll see a pin on either side of the console down where the pedalboard slides in. You'll also see corresponding sheet metal hooks on either side of the pedalboard. It's important that these "hooks" slide over and engage the pins. You'll know you have it right if you can not simply pull the pedalboard back without lifting the front of the pedalboard (by the console). It's also possible the height of the board needs to be adjusted on either side to properly actuate the switches.

The dead 2' stops are another problem unless Rodgers started using multiple switches per note. The designs I'm familiar with have only one switch and all the stop switching is done electronically so the 2's not working could be an involved problem.

As for replacing the thumb piston, you may want to contact Jan Girardot ("Jan the Organ Grinder") on this forum. I remember that, in his For Sale list, he had some Rodgers thumb pistons that were already engraved. If he has the particular number you need, you'll be in business. If you can't find him elsewhere here, let me know and I'll notify him your looking for him. He may even have a Service Manual for this organ.

I don't know that Syndyne deals with individuals and, if they do, that they provide engraving.

Why would you want to grease the volume pedal mechanism?

Greg

[davidb]

Thanks, Greg. I'll check to see if there is more than one switch per pedal. If not, then the "missing" 16' AND the "missing" 2' stops seem to be a bigger issue.

I'll look for Jan's contact info here, and notify you if I can't find it.

The volume pedals were verrrrry hard to move. Each one has a metal bar with a slot in it, through which a bolt passes (for adjustment obviously). The bar is sandwiched between two (what looks like) heavy felt disks. The pedal moves the bar long-wise which in turn turns the potentiometer. The disks obviously had once been soaked with oil, because if I pushed on them gently with a flat screwdriver tip, oil squeezed out. But they were very, very dry. I added a few drops of oil, which they absorbed nicely, and the mechanisms move much better now.

Thanks again,

David

[Jan Girardot]

Hello, DavidB;

Jan, here, with the short list of Rodgers pistons for sale:
thumb piston, ‘0’ $10
thumb piston, ‘4’ $10
thumb piston, ‘7’ $10
Contact me with a PM or off Forum at [email protected] for further info.

. . . Jan
the OrganGrinder

[davidb]

Thanks, Jan. Naturally, I need a "3". I guess I'll try finding a "3"; if I strike out, I'll circle back to you and maybe we'll just have two "4"s.

By the way, any helpful troubleshooting tips about the missing 16' stops on SOME of the foot pedals? And the fact that none of the pedals play 2' stops?

Thanks again.

[indianajo]

It is good to push the actuator button or whatever there is (reed switch) by hand to eliminate mechanical problems caused by moving. My organs, one has buttons on microswitches in a box you can push by hand (everything worked that way) the other organ has reed switches on the pedal set that you can trip manually with a small bar magnet. Tne nearest I have gotten to an actual Rogers is viewing one from the second pew, as only graduate performers with a performance degree touch the organ in our church.
As for the 2', look at the schematic before making a call. You could have power supply problems, you could have dirty contact problems in a tab, you could have a dirty level pot somewhere. If there is one contact on the pedals, probably they used SS CMOS switches to do the switching, which were pretty cheap after 1980.

[davidb]

Thanks indianjo.

I've ordered a technical manual, so hopefully that'll help debug the issue. I have discovered that the 16' stops that don't work, don't work AT ALL: the same notes that don't play on the pedals, also don't play on either of the keyboards. And I did test the pedals with a magnet, and they all look good.