Conn 650 Key Contact Cleaning

**Hamman** · 05-08-2012, 03:17 PM

Does somebody have any suggestions on any tried and proved method of cleaning key contacts in a Conn 650 without removing the rods??

**Hamman** · 05-09-2012, 09:14 PM

Ok 41 views and no suggestions....I know it plainly states underneath the keyboards next to the key contact whiskers not to "spray" contact cleaner or use "lube" on the key contacts....but could I use deoxit contact cleaner on a cotton swab and clean the whisker contacts? I'm wondering if the caution decal was meant for all the over spray and resistance issues associated with "global" spraying of the key contacts?

**Jan Girardot** · 05-09-2012, 11:29 PM

I forget, does that model Conn have the vinyl buss bars?

. . . Jan
the OrganGrinder

**twnelson** · 05-10-2012, 02:40 AM

Yes, that one has the nefarious conductive vinyl rods. I typically used a swab with isopropyl alcohol to clean the vinyl surface as best possible. Sometimes it was necessary to shift the whole rod to one side or the other to avoid badly worn spots.

--- Tom

**Jan Girardot** · 05-10-2012, 05:30 AM

Hamman:

While I wish you the best of luck cleaning your conductive vinyl rods (assuming yours hasn't had the vinyls replaced with gold or some other metal rods), it must be said that the real, deep-seated problem with the vinyl rods is not stuff building up on them. Let us know which busses you have, please.

. . . Jan
the OrganGrinder

**Hamman** · 05-10-2012, 02:34 PM

Thanks everyone who responded! It seems that my upper most manual is having the non-responsive note playing issue. If I manipulate the key action a little I can get the tone to come through. But when I go to play that note(s) again it fails to come through until again I play around with that note by striking it or slowly depressing it to try to get it to sound fully. The lower 2 manuals just have that issue with a few notes each and isn't so bothersome. This is only happening with the complex voices not the Tibias. I try and play on this organ daily to "wear" in a contact path like I did on my 651 which worked for it but not this 650. If I open up the manual and physically take the whisker contact and lightly rub it a little side to side on the buss bar rod I can get it to sound. So I cancelled the presets and stops (rotated the buss bar into no play position) and wiped down the contact portion of the rod as best as I could (was some blackness to the cloth) but that didn't do a darn thing for the issue. I then "shifted the buss bar rod down a little and that seem to make it worse (the other playing keys now would have issues....also I was leary of doing that in the first place since I run into that on Hammonds quite a bit). So is my issue in the "whisker" contact wire of the individual notes ? Or is this looking to be something deeper then I was hoping it wouldn't be? I know the vinyl rods have be mentioned as suspect in these issues before but why would that be if it has a clean un-obstructed contact point?

**Jan Girardot** · 05-10-2012, 04:40 PM

Hamman:

I think you will find Conn's vinyl buss bars discussed at great length in this Forum's archives. Here is a brief recap: the problem is not in the key whisker, it is in the buss itself. What Conn found was that the metal "drain" wire that runs down the middle of the buss is coming loose from the black vinyl material. Because of that detachment, the audio signal on the whisker can't reliably reach the drain wire which is attached to preamps, etc.

The only reliable fix is to replace the busses with gold-plated rods. I don't know if Carla at Organ Svce. Corp. has any more, but give it a try.

. . . Jan
the OrganGrinder

**Hamman** · 05-10-2012, 05:49 PM

Thanks Jan, I was hoping you would chime in again. I know this subject has been beaten to death but trying to do a search on this forum site is ridiculous. Somehow it just shows results for most recent posts regardless of the subject title I put into search. Anyway, I do see the "metallic" contact piece running down the length of the vinyl rod...which looks to be connected to the wire on the end. Isn't the vinyl just a insulator? Is this piece of contact wire (for a lack of a better term) that is running down the length of the vinyl buss bar special in the sense of being a resistive type wire? Or is it just the core material of what this contact buss is made of that is failing/ breaking down?

**toodles** · 05-10-2012, 05:59 PM

The vinyl is impregnated with carbon particles, which turns it into a conductor of sorts--really more of a resistor. That's the black you found on your cloth when you wiped the rods. The resistance through the vinyl to the center conductor is low, but along the full length of the rod, it's quite a bit. This is why it would be critical for the center rod to make good contact to the vinyl.

The choice of this material was a bad idea, in my engineering opinion, but it was much cheaper than gold clad rods. Gold rods are the answer, but if there are lots of pitches, it becomes expensive to replace them all.

Toodles

**indianajo** · 05-10-2012, 06:05 PM

I always search anymore by putting "organforum.com: "search title"" in the google box. organforum search or's the results for each search word individually, even with quotes around the string.
I'm glad to hear my prejudice against Conn's that might have vinyl bus rods is justified. I've passed up several big theater Conn's, as the factory was in Madison, IN and they were dominent in this market. Up to now I had only seen the plastic rods in a picture of the pedal unit of an old tube Conn on electronics forum.
If you can't get nickel, stainless, or precious metal bus rod somewhere, I would be tempted to salvage the Conn electronics if I really liked them, and put them on Wurlitzer or hammond keyboard. Or even an unrepairable Allen. Allen electronic service ability and practices is really being dissed today on the electronics forum. They do seem to have precious metal contacts.