Roland FP-4 Keyboard HELP

[Piano4U]

Yes I know I've more than got my money out of this keyboard but I'm trying to extend its life a little longer. I have one key that is acting-up and if someone can help me with this I will be forever grateful 😁. When I press the key down the volume is normal but when I release the key it plays the note for a fraction of a second at maximum velocity. (See attached Video) Any help is greatly appreciated!! I remember someone on this forum (I think it was user Jazz+) knew a lot about theses keyboards.

[Joe Muscara]

My first guess would be a dirty sensor. Does it do it on all tones?

 

Some people have had success cleaning dirty sensors on some keyboards by blowing compressed air between the keys and working the key.

[Coker]

After trying to clean the 2 sensors, I would take a look at the circuit board that has the sensors on it. It seems too regular to be a dirty contact. You may have a cracked trace or failed component like a diode or cap. Try to see how voltages behave on the adjacent key’s circuitry compared to the faulty key’s circuitry. 
 

First, though, see if you can make the problem go away or move to a different note by turning the fp4 upside-down and shaking it.

 

good luck.

[Piano4U]

On 2/24/2022 at 3:17 PM, Joe Muscara said:

My first guess would be a dirty sensor. Does it do it on all tones?

 

Some people have had success cleaning dirty sensors on some keyboards by blowing compressed air between the keys and working the key.

That's kind of what I thought - I will give that a try.Thanks!

[Piano4U]

On 2/24/2022 at 4:11 PM, Coker said:

After trying to clean the 2 sensors, I would take a look at the circuit board that has the sensors on it. It seems too regular to be a dirty contact. You may have a cracked trace or failed component like a diode or cap. Try to see how voltages behave on the adjacent key’s circuitry compared to the faulty key’s circuitry. 
 

First, though, see if you can make the problem go away or move to a different note by turning the fp4 upside-down and shaking it.

 

good luck.

Thanks for the advice. I wanted to avoid taking the thing apart but if cleaning things from the outside doesn't work I don't think I'll have any choice. It is only the one key that is causing the problem.

[Piano4U]

Tried the compressed air and tipping upside down - no luck. Looks like I will taking out a whole bunch of screws to get inside that beast.

[Coker]

It’s not too bad.  I did it about 4 times with mine.  The last time was to replace the entire keybed, which had started to crack in different places.  They would a sell only the entire assembly, not octaves.  Be careful of the multiple screw sizes.

[16251]

Just avoid that Bb, there are still 87 playable keys. 

[cjfox]

I've never had lasting success cleaning the contacts, replacing the rubber strip of contacts was the way to go for with a couple of Roland pianos I had. The dynamic response was off on a lot the keys, not when releasing the keys, but your problem sounds similar. Unfortunately Roland will no longer sell replacement parts to an individual, you now have to go through an "authorized dealer" so if you are in major metropolitan area, you might be OK finding the contact strips.

[Coker]

And you can always swap the offending strip with one at the top or bottom of the keyboard.

[Piano4U]

Ok thanks for the helpful info. I will see if there is an authorized dealer in my area. I may also try that suggestion of swapping out the contacts from the very bottom of the keyboard. - I will let you know how it goes. Thanks again for the input fellas. 👍