Piano, Organ, and Keyboard/LOWREY GENIUS G100

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QUESTION: Hello Thomas, I saw you answered another ? about this unit. Just got on from wife's parents that was my wife's when she was a kid about 1988 till 1998. Kept in the house unused till now, 2014. It powers on with power light. Screen works as do all the sound function numbered keys. Volume keys work but don't have cartridges to test that. Most of the keys work fine, but there are several that do not make any sound. (The 14 high keys along with a couple random in the middle range and then a block of 3 near the low end.) 1 low key has a "stutter".
I have dusted, vacuumed,and compressed air cleaned it with no effect. I have also manually checked each connection I could get to. Any assistance on fixing or at least trouble shooting is greatly appreciated. Especially before I try to disassemble it or something.
Thank you very much and have a great week,

ANSWER: Hello Rocky,  According to my documentation, this instrument uses a digital master IC to run the entire organ.  If something goes wrong with the IC, there isn't much that can be done because parts are essentially nonexistent. Allowing electronics to sit around unused for long periods of time is really hard on the components.  Hopefully, the problem is limited to a few bad connections, broken wires or dirty contacts.  The only way to determine this is to dig into the circuitry and start troubleshooting...starting with the power supply.  Because the electronics is very sensitive to static charges, care must be taken to prevent static damage by always keeping yourself grounded through a grounding strap or similar device.  It would be a shame to find a few bad contacts and in the process of doing so loose the IC's to static damage.

It is curious though, your description suggests the instrument utilizes frequency dividers.  If this is the case, the top octave tones are digitally generated then each tone is sent through a series of frequency dividers which provide all the octave pitches below the top octave.  As the frequency divider circuitry fails, you loose more and more notes below the top octave.  This sounds like what you have described.  To troubleshoot frequency dividers, a simple signal tracer is the fastest way to determine which dividers are at fault.

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QUESTION: what is a signal tracer? Would I buy at Frys electronics or something?
I cleaned the piano thoroughly and now all the keys work except the high 13 or so all in a row. Does that now REALLY sound like the frequency divider and not the IC?
Thank you for the assistance!

Answer
In rereading all you have reported and confirming the organ uses digital tone production, I believe you probably have an electronic problem that no amount of cleaning is going to solve.  If the keyboards are set up with a diode matrix, there may be some cracked diodes, broken wires or corroded contacts.  If the keyboards use collector chips then you may have some bad keyboard IC's. I would need to see the instrument to determine what the most likely issue is.  In these instruments, one main IC runs the entire organ.  If something goes wrong with that chip, there is little you can do other than find a replacement IC...or another organ.  

If it is a matter of not being able to afford a service call, then go ahead and disassemble the instrument enough to visualize the underside of the keyboards.  You will be looking for corrosion, broken wires, anything that looks questionable.  If there is nothing obvious, a professional will need to be called in, or...try going to a website like craigslist.com and check out inexpensive organs that are available in your area.  Don't overlook the "free stuff" category.  A lot of time people just give away perfectly good organs.  

Piano, Organ, and Keyboard

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Thomas Britanyak

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I am a full time organ/piano technician who has been actively involved with the design, building, repair, maintenance and installation of organs and pianos for 35 years. I began as a keyboard instrument apprentice and hold degrees in music and electronics. If you need a piano's date of manufacture, please go to http://www.pianoexchange.com/howold.htm or http://www.bluebookofpianos.com/pianoage.html I am happy to answer musical or technical questions, however, I CANNOT offer appraisals on pianos or organs. Please do not ask what an instrument is worth. For this service please contact an experienced local appraiser or try the following links: https://mmm1100.verio-web.com/blueb1/appraisal.html or http://www.57piano.com/questions.htm

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I am a full time organ/piano technician who has been actively involved with the design, building, repair, maintenance and installation of organs and pianos for 35 years. I began as a keyboard instrument apprentice and hold degrees in music and electronics.

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I am a full time organ/piano technician who has been actively involved with the design, building, repair, maintenance and installation of organs and pianos for 35 years. I began as a keyboard instrument apprentice and hold degrees in music and electronics.

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