Casio Privia PX-3s full velocity middle E only

Single note gives full velocity, noted with MIDI signal out as well. I have opened the unit, first used compressed air at the pad, without success, then used isopropyl alcohol, also unsuccessful. Would this indicate a circuit board issue rather than the contact? any suggestions welcome.

which note exactly - will then get back with exact trace to check …

E above middle C, 26th white key from the left. Thank you!

It’s most probably (99%) on the middle circuit board underneath the keys (E4… counting from left first note being A0). Either a faulty diode or more likely a broken trace.

However, I forgot to ask one other thing … that white key hasn’t dropped by about 3mm compared to other keys? Or alternatively, and I have seen that too, all keys have dropped by about 3mm, hence you cannot see a difference, but ALL keys have a 3mm play lifting the white keys up.

Just verify that for me first please - if that is the case then the rubber key caps need to be replaced along the entire key frame.


No vertical play in key and not dropped. Is there a fix for the circuit board or is a replacement board available?

Thank you!

Problem is located on a circuit board underneath the keys. The entire keyframe needs to be removed, and all keys from left to right need to be removed and/or lifted. This exposes a set of 3 circuit boards that need to be removed. This then exposes a set of 4 circuit boards and the problem is on the second from the left of those circuit boards, last contact on the right of the second board. These boards need to be remoted as well which then exposes the primary rubber contacts. It could be just a bad rubber contact in which case you just remove the strip of 12 that traverses the E4 (last contact of second board from left and clean it and also inspect the board itself for a broken track. If that seems OK visually you can go and measure continuity with a DVM.
Alternatively just replace that board - only comes as a set of two (the two left being KYA1 - KYA2, the two on the right being KYB1-KYB2)
Part number for the left set is:
10341198 PCB ASSY/KYA TK-RJM509622*001

It is not an easy job by the way !!

I had exactly the same problem with my Privia PX-3. I had to replace the diode for that note on the keypad circuit board. It’s not that difficult of a fix but I found the biggest challenge was to get the keyboard assembly out of the instrument so that I could work on it. Lots of screws and removal of keys to get to the offending diode to replace. I guess you could simply clip the bad diode’s leads and resolder the new diode leads to the orphaned leads. Be sure and note the polarity of the diode with regards to the defective one.

Before doing all this be sure that the contact strip doesn’t have a small tear on the rubber contact strip itself. You could switch the whole 12 note contact strip with another one on the key contact board and see if the problem migrates to another area. This would confirm that it is a contact strip issue rather than a diode problem.

Thank you for your help! There are 2 layers of circuits under the keys - is this the upper or lower circuit?

Lower, the one with the four circuit boards