JP-8000 Sticky keys

Fixed the problem. Good to go now.

How did you fixed it?
I have some sticky notes on my JP-8000.
I couldn't find inside the keyboard what makes it sticky.

Thanks

The sticky keys actually have nothing to do with the grease. It's the springs. The springs lose tension over time and do not lift the key back into shape. You simply have to remove the key and pull the springs to lengthen them a bit. This increases the tension and everything will work great again. You can clean up and replace the grease with fresh amounts which I did as well. However, it's the spring tension that is the culprit. This is why after cleaning the grease the problem continues. Nobody thinks to check the spring tension. Hope this helps.

Hello and thanks for your insight!

One question: is it the same problem if the button seems to do not actually "press" ?
On my unit, some buttons tend to do not execute the pressing and I have to press harder them in order to have a LED to be lit/unlit etc...

If this my case has to do with grease....can you please recommend me one ?

Thank you very much in advance!
GiGi
d^_^b

Well after investigating the problem, I finally found what makes the key to sticky.
Under every key, close to the front, there is a small black rectangle plastic that comes from the bottom.
When pressing a white key, the underneath of the key is surrounding the black rectangle.
My guess is that over the years the plastic of the keys is shrink a little bit which can cause the problem.

By peeling off half millimeter of this rectangle will let the key moves again as it should.
I had lots of sticky keys, especially A B G & F, I did the above and it's great now.
Once I have a chance to open my JP-8000 again, I'll take some pics and video.

the one who recommends and tries to stretch the springs under the keys is mistaken and makes nonsense, as this affects the force / elasticity of the resistance of the keys! you won't be able to stretch evenly and I doubt you're using a dynamometer for this kind of task! and thus you will ruin the keyboard in this way (those who own the instrument at least above average and have the qualifications of a piano-player will immediately notice and will treat such a keyboard as a marriage with an uneven response from the keys)
The reasons for "sticky keyboard" is several:
- aging, degradation of the lubricant, which becomes like "plasticine" for children's stucco work ...
- excessive presence of this lubrication under the black stop in the middle of the key, which can get not only along the sliding of the key along the stop, but also upwards between the bottom of the keyboard = which ultimately leads to a random sticking effect due to an increase in tearing force from stuck together surfaces (like creating a vacuum like in a medical syringe or a hand pump for a bicycle in which the needle is clogged)
- well, the generative effect gives dust and dirt that has accumulated under the keyboard for several decades - even a small hair or thread adhering to sliding surfaces gives a reinforcing effect for such a lubricant.
I also noticed that the entire metal surface of the attachment of the JP-8000 keyboard is also lubricated and, in combination with the dust that has fallen on this surface, leads to such contamination (like a sloppy housewife in the kitchen - everything is in grease and dirt from cooking and the lack of cleaning body fat) - all this is not the fault of the owner. but most likely - the old practice of abundant lubrication of the manufacturer's surfaces, when the technology of the synthesizer keyboard of the 80-90s was still honed;
Based on the foregoing, mechanical cleaning of the old grease from rubbing parts and the entire surface under the keyboard is required (I spent almost a pack of paper napkins for this with 100% dismantling of all keys - see photo). after which it was necessary to wash off all the keys from the lubricant in the foam solution and the slurry from the undissolved dirt, followed by drying the paste during the day)

I will add another 5 cents to the problem fix the keys sticking on the Roland JP-8000:
I cleaned from gears grease on frame of the synthesizer keys three times, with a full cleaning and replacement of the lubricant. but in the end I had to use the most severe method, since all the other measures described above helped only for a while. After which the keys still stuck with variable constancy...
the initial the keys gap was within 0.25 mm! and with a small skew of the keys axe - it creates a small friction. which is enough for the key to stick in the pressed state...
The method consists of filing off a thin layer on the plastic stumps that are under the front edge of the key, which were discussed here earlier - the procedure is painstaking and time-consuming, since the plastic is made of a hard polymer or nylon. When filing manually with a file, burrs appear, which, if not removed, can lead to an even greater number of jammed keys. therefore, it was necessary to grind down a little more than desired, in order to increase the gap between the plastic of the key and the nylon stump-stop of the frame. and after this procedure, it is necessary to check and cut off all the burrs of the nylon.
And working with a dimmer is not a very good solution, because the dimmer disk either quickly gets clogged with nylon or begins to melt the nylon and then there are deposits on the sides of the ends, which will definitely not allow the keys to move freely up and down. But it is possible to check and identify defects may be only after completely combine the keyboard.
So it was necessary to correct the mistakes three or four times and bring all 49 stumps under of the keys to an ideal state by each side.
This is how it looked during the sharpening of the keyboard frame:

now - it works fine!