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A#5 acting strange


Fenderbridge

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Good day!  First post here!

My PX-5S is out of warranty, so I had no qualms about opening 'er right up.  

 

Long and short of it is, when I hit the A#5 key at about a 100 - 127 velocity, the note registers as a key press on and immediately off.  So I press the key hard, and the grand piano sound goes "tink" when I hold it down, instead of going "TIIIIIiiiiiinnnnnnnnn--".  It's as if I tap the key and let go really quick.

After the "tink" noise, if I let go, it'll make the same noise again, "tink".   Again, the "tink" is just the sound that the piano voice makes (and I did try more than one voice), not the keybed itself.  Essentially, if I 100-127 it, it doesn't register as a sustained note, but rather as a quick tap, and then registers again when I let go.  It's a very, VERY odd situation.

 

So, I opened 'er up, blew her out, and same deal, no fixy.  So I am at a bit of a loss here.

 

I removed all of the screws, bringing out the keybed en masse, and for the absolute life of me, I am unable to figure out how to remove the A#5 key, or any other key for that matter.  There aren't any other screws to be removed, and the only thing I can think of is prying apart the "spine" holding the key in at the first fulcrum at the top of the key, but I'm afraid that may break it.  and if I break that plastic, I'd have to replace the entire plastic keybed (not keys), and I'm sure that'd be a special type of hell to replace.

 

I looked all over the forum, all over youtube and google trying to figure out the best way to remove or replace a key on a PX-5S, but didn't find a thing.  I even looked for the PX-530 since apparently they have the same mechanism, but no dice.  I looked at other brands tear-down videos, but casio is proprietary in the way that their keys go in, so no luck there.

 

I spoke with Casio tech support, and they pointed me to this forum.  I am sure one of you guys have torn down a PX-5S before.

 

Thanks ahead for the help, I have a big show on Friday :)

 

 

EDIT**

 

Looks like I'm not the only one.  Thanks to John Pittas on the facebook forum for PX-5S for sharing the video.  This is the exact thing that happens to me, same key, too.

 

 

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Hi Fenderbridge - really sorry you're having this problem, and I can't contribute to the "how to remove/repair a key", but as a puzzle solver,

I have two questions:

 

1)  Does this happen with no cables connected to the PX-5S (other than power)?

 

2)  I'm wondering what the MIDI Output from the PX-5S looks like when you're hearing that "key-down/key-up double-TINK" sound?  You could see the MIDI messages by connecting to a computer via USB (or via the 5-pin DIN into a MIDI interface) and running (for example on a Mac) 'MIDI Monitor' (MIDI-OX should do this on a PC).

 

Not trying to make things more complex for you - but sometimes a bit more info helps.

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There is a trick to removing the key, but its been awhile, I'm fuzzy remembering exactly (on my PX350 which has the same key structure inside). You must have clearance to be able to pull the key forward and up, and when you put it back in, it feels even trickier to get it back because of the structure of the rear of the key underneath. I discovered this by accident, as one of my keys had popped out and up about 1/2" and i thought it was broken .i remember it took some doing to get it back just right. A single key can be removed though. I had the entire keybed out when i did it, not a n easy job as you have probably already discovered. The key clicks in place once it is removed, at least that's as clear as i remember.

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I am having the same problem on A#5. Not so much the cutoff, but definitely the double-strike upon release at higher velocity.  I bought my PX5S used in March 2016 (out of warranty); this problem began in August.

 

Suspecting some dust or foreign object had somehow gotten into the sensor, I took the keyboard apart and completely cleaned the rubber/vinyl contact and the circuit board using compressed air and CRC Electronic Cleaner.  The first time I thought I solved the problem, because it was fine for about 2 weeks.  (I play full-time in local clubs, and use the PX5S 2-4 times weekly,  Yamaha S90ES or CP30 on the rest of the gigs).

However, the double-strike returned. I again took apart the keyboard and cleaned the sensors, but this time it did not stop the problem.  I suspect the contact may not be seating properly into the circuit board, or it is worn and now responds erratically.

 

Also, the B5 note has begun to stick on occasion.

 

Unless someone has a better idea, when I have time I'll open it up again, and see if I can switch the suspect contact strip with another on the lower part of the keyboard.  If I can, and there's any difference, I'll let y'all know and post photos/video.

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  • 3 weeks later...

Hey, I have the exact same problem! I'm (slightly) relieved to see that others do too, because maybe there's an agreed-upon fix. Mine also is an A#, but is 3 octaves lower. I happen to still be in warranty, but I'm not sure how I'd deal with not having the unit if I were to send it in to be fixed. On the other hand, I'm willing to take it apart myself and void the remaining 3 months of warranty if there were clear instructions on how to do so. 

Any comments by official reps?

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  • 1 month later...

That's my video above. I just got the board back from the repair shop, and the problem is fixed. The repair description reads: "Replaced rubber contact containing specific key. Cleaned contact PCB under specific key. Tested all keys for proper triggering." I hope that's the last of my keybed problems for a while. I have now spent a third of the purchase price on repairs. My bank select button is acting up, too; half the time it doesn't register. I hope it's not on it's way out; it looks like others have a similar problem based on recent posts in the FB group.

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  • 10 months later...

Yep, I'm having the same problem with the Bb key almost 2 octaves above middle C, so that is probably the same key.  Weird that it is the same key for everybody.  I'd love to hear a good answer because it is driving me crazy!!  I find myself avoiding playing this key all the time now.  Wow, your posts are from 2016 and it is now September 2017.  Did anybody get a solution??

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  • 2 months later...

I guess my problem isn't the same, but it's the same key Bb.  It sounds fine when I play it, but if I hold it for more than a second, when I lift up the Bb note sounds AGAIN very loudly.  Has anybody had this problem as well?  Thanks Brad for the air tip, I'll try that and see if it works!

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  • 2 weeks later...

Just tore down my PX today, and just made a thread on it further up the forum, but I have a theory that the reason it's usually the A# key is because it's close to a junction where two boards meet, and the rubber sort of ripples up in that location allowing contaminants to get under it near the A# and B key contacts.

 

Ivan

 

IMG_0734.JPG

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I agree. I found moisture on the circuit board underneath the contacts several times.

 

Since I play at least 3 different gigs weekly, changing environments contributed heavily to the condensation, and compressed air didn't really do the trick.  So my PX5 has been relegated to rehearsal use only, and I now use a CP4 for gigs.  

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  • 5 months later...
On 12/13/2017 at 10:37 PM, Dshoff said:

I guess my problem isn't the same, but it's the same key Bb.  It sounds fine when I play it, but if I hold it for more than a second, when I lift up the Bb note sounds AGAIN very loudly.  Has anybody had this problem as well?  Thanks Brad for the air tip, I'll try that and see if it works!

Me too. Same problem, same note.......isn't that WEIRD? Probably just coincidence, but still.....

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  • 2 years later...

I guess I've been lucky. I had no problems with the PX-5S until the beginning of 2020 and bought it July 2014. Same problem. Bb 6 give a single "think" then re-triggers when it's released. I think craZivin is right, that's where the boards meet. I'll try blowing it out first.

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The carbon contacts inside the rubber boots, and the boot itself are both very sensitive parts-the least bit of contamination can cause no end of problems as you've all discovered. And yes, any section of the keyboard where these strips do not sit solidly will cause these problems-I've dealt with this on many keyboards unfortunately over time. The most difficult part to repair-when the rubber boots wear- each cup section must contact the circuit board traces underneath and  inside exactly right-and are ever so slightly different for each of the 3 (or 2 in other keys) rubber cups-this is why the first thing to go will be the dynamic response to a key. And do not clean the contacts with anything but water-and distilled water if you can, as even the slightest contamination will destroy the conductivity.

 

There are tiny "nibs" on the strips that fit into the circuit board-these can push out of the respective IC board holes over time or worse, break completely-now nothing but gravity is holding the rubber strips in place-some manufacturer's boards use some kind of glue to keep the rubber strips in place in addition to the physical nibs-I uses a sharp tool to push these back in place-but be careful not to push too hard which will cut the rubber. In some problem boards-where the rubber strip is not snug against the IC board below-where every key strike is going to unseat the rubber again (why certain keys fail again even when repaired-watch the end joints of the rubber strips, this is usually where I have had bad keys-I use very thin double sided tape to secure the boot-very tiny pieces only, and very thin as raising the boot even a microscopic bit will run it's response.

 

 As far as conductive carbon "glue" not all brands will work-and another very difficult repair-if you change the thickness of the carbon contacts at all-your dynamic response will be ruined! The space between the carbon boot and the circuit board is critical, i discovered this the hard way. Some people claim the graphite in a pencil is better-but I haven't had much luck with that either. The best repair=replace the entire boot strip-and even that, if not done exactly right-will give you alot of grief, again because unless the rubber strip is placed very tightly against the circuit board, and positioned exactly as it needs to be-aaarrrggghhh! So even if you clean the boot-if the seal between the board and the boot is not tight-contamination will get in again. I am guessing that with the original problem rubber strips with boots-once the boot is distorted by playing-it will not sit perfectly flat anymore on the IC board, and your problem key will fail again, even after you clean it. 

 

Why all these problems? Even though this boot material is a very resilient silicon rubber-repeated playing will distort the shape of the cups-to the point of not being repairable-must be replaced with new-and as I've already said-even the tiniest distortion of the shape and profile of even one cup-will ruin the key response-I've lost hours going through this with many boards-the Casios seem more resilient over time so far. Only a complete redesign of the rubber boot material could solve this problem-a daunting task as the existing material is probably as good as it gets from a manufacturer's point of view, and would probably require the entire industry-that manufactures these boots to change the materials or basic design.  

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  • 4 weeks later...

A#3 is acting up for me 😐 - dynamic response is gone half of the time (going in at max volume with the slightest keypress).

 

Playing the key loudly usually fixes it for a while. 

 

Does that mean the cup is a goner and needs repair, or could compressed air still fix this?

 

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  • 4 weeks later...

This is so weird -- A# 6 is acting up for ME now. Sometimes I hit it and it sounds normal at first but then releases even though I didn't let up on the key. I hope that metallic paper thing works -- and that I don't break the piano when I open it up! I know there are instructions on the forum here about how to do it. I'll report what happens when I get around to doing it.


I just find it incredibly strange that it's all A#s in various locations. I've never really studied the interior, so does anyone see a connection to them all?

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From another discussion about this issue.....this seems to have fixed the propblem for me as well.....Thanks, Redwave!

"It happened on the Ab below middle C for me. Since the second strike is velocity 127 which I rarely if ever generate in my playing, I was able to work around the problem by setting maximum velocity to 126 in every zone which includes this key (in stage settings where I actually need this particular note). The second strike then disappears and the first strike sounds normally."

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