Repairing Faulty Keys
Units I own
Victor's produced it's first keyboard instrument, the EO-4420, in 1958. It was also the first electronic organ produced in Victor's native Japan. This was followed with a long line of instruments and it seems with great success. It wasn't until the late 70s / early 80s that Victor sold keyboards and organs outside Japan where it is know as JVC (Victor Company of Japan). In America it's instruments were rebranded under the Lowrey name. Throughout this site I will refer to all these instruments using the JVC name unless I am making reference to a particular instrument under a different brand name.
JVC released it's last model in 1985, the NS-70. It kept producing this until 1991 when it closed it's musical instrument division. I can only assume the reason for this was poor sales. It seems that their instruments were at best only moderately successful outside Japan and their was perhaps a lack of innovation with some of their later instruments. The NS-70 is a fine instrument but at it's 1985 launch it was a bit behind the times with it's subtractive analogue voice architecture. As I understand it in 1991 Victor's music school in Japan (a significant part of it's musical business) merged with Technics' music school to form Victor Technics Music. In 2001 it was somehow absorbed into Roland Music Studio which is still in operation today.
their relative obscurity outside Japan I think JVC's instruments showed
a very high standard of design with a very charismatic sound. This site
is dedicated to gathering complete information related to all JVC organs
Most JVCs I've owned have had keys that are either intermittent or dead. I've been able to repair these machines with reasonable success, although if it is not used regularly it can go back to not working so well. Each key presses on a closed rubber dome which must contain a conductive surface. It seems unconductive matter forms and so decreases the key's responsiveness. Ultimately you'd want to take these rubber domes off to clean the contacts but unfortunately they are not removable. However pressing directly on them with your finger to dislodge the matter works very well. Below is the procedure to do this. Do not do this unless you are a qualified electronics technician. Electric shock risk!
1. Go through each key and note down which are faulty.
2. Disconnect unit from power supply and leave time for capacitors to discharge.
3. Remove all screws on the under side of the unit and take off the back.
4. You now want to remove the keyboard assembly. To do this you'll have to carefully look around inside and work out which screws and plugs need to be removed. Take very careful note of what you do including where the ground cord goes so that you know how to put it back together! Remove the keyboard assembly.
5. Take out the offending keys. To do this press a finger quiet hard on the end of the key farthest away from you if you were facing the keyboard as if you where playing it. With the other hand pull the key towards your body. You'll now be able to see the rubber dome. Especially for black keys you may need to remove a few keys around it too get good access. Now with a finger repeatedly press the rubber dome. One minute is probably long enough, but you may as well do it for longer seeing you've gone to all this trouble.
Now replace the keys and reassemble the unit.
|JVC/Victor Official Site||Global||Contact JVC/Victor in your country for help with manuals|
|High Country Service Data||Australia|
|WD Greenhill & Co||UK|
|Organ Service Corporation||US||JVC related Lowrey manuals|
|Johannes Vrana's Homepage||Germany||Click "Bedienungsanleitungen / Manuals" to find PDFs of KB-500 and KB-800 owner's manuals|
|Organ Service Corporation||US||Parts for JVC related Lowrey units|
JVC KB-500F (silver version)
Lowrey Micro Genie V-60
Lowrey Micro Genie V-120
Lowrey Guitar Strumboard KG-100
Lowrey Rhythm Module KL-101