I bought a Roland JV-80 synthesizer that was advertized as not working correctly.
It’s a 1992 synthesizer that lay the foundations for the JV-1080, JV-2080 and the XP-series synths. It’s got 61 semi-weighted keys and 28 note polyphony.
I went to see the synth and found out that some keys didn’t work. As a matter of fact: some keys couldn’t even be pressed down because it felt like they were glued to each other.
The JV-80 came with a stand, a flightcase and a SO-PCM1-01 Piano Sound library and a PN-JV80-06 Orchestral patch data card. When I took the JV-80 apart at home I discovered that a SR-JV80-18 Latin Expansion board was also installed. Bonus!
The problem with the sticky keys is very common with 80’s and 90’s Rolands. Synths from that era have weights glued to the bottom of the keys to make them heavier and provide a better feel when playing. Unfortunatly this glue starts to run sometimes making a mess of the inside of the synth.
The fix isn’t very difficult. It will take one or two evenings but it’s very do-able.
You need to take the keybed apart and remove all the keys. Then you need to soak the keys in a chemical solution called ‘Caustic soda’. This is a little dangerous because it’s basically drain cleaner so wear rubber gloves and eye protection because this stuff can cause burns.
The chemical needed is Sodium Hydroxide which is the main component in some draincleaners. I always buy the dry grainy stuff that looks like salt (but bigger grains) instead of the liquid drain cleaner. The bottle of the product I buy says ‘100% Sodium Hydroxide’ (Natrium Hydroxide in Dutch) on the back. I buy it at a shop called Kruidvat here in the Netherlands.
Disclaimer: do this at your own risk 🙂
I always mix 50 grams of sodium hydroxide per liter of water. This causes an exothemic reaction (water gets hot fast) so be carefull and wear rubber gloves and eye protection. Always use a plastic container for the liquid because it can damage metals and stone (remember the bathtub scene in Breaking Bad 🙂 I don’t know if they used caustic soda but you get the idea). I let the keys soak for a while and refresh the liquid once or twice. Seeing the red glue disappear is like watching snow melt in the sun. The weights should fall out all by themselves when you pickup the keys. Rinse the keys and the weights very thoroughly with water after you are done. If you leave the metal weights in the liquid to long a little surface rust can appear on them.
It can take a while before the weights from the black keys fall out but they should drop out all by them selves. If this doesn’t happen after a few hours of soaking refresh the solution.
When everything is nice and clean take some good glue and glue the weights back in. Reassemble everything and you’re done!
I now have a perfecly working JV-80 🙂