mik pointe

Sure thing, and thanks too. I updated it to reflect that it's the time between sensor hits that determines velocity - not the force per say. Have a nice day

I solved this issue. It took a lot of exploration. For anybody else pulling their hair out over this issue... There a tri sensor rubber contact - the one towards the front seems to control high velocity in a sense, even though it's the time between the strikes of the different sensors that calculates the velocity methinks. The bottom of the black and white keys, as well as the black and white keys' rubber contacts are different from each other by design. In my unit, the angle of the rubber contact pcb was such that the white keys were striking the front contact pad too late, causing them all to sound unnaturally loud (hitting the other sensors too soon after, thus tricking it into thinking I was playing louder). I was able to correct the angle by literally putting VERY thin carboard as washers, under the screws that hold the Rubber Key PCB to the rest of the keyboard, thus changing the angle so that the keys weren't hitting the front pad at the wrong time. The result is that the keyboard plays correctly now!!!!! This is a picture of the difference that the cardboard made. In a perfect world, one could use washers that were the right size. I imagine that this is a factory defect, as I've come across a few folks that have had this issue. This works because the black keys rest closer to the pads than do the white keys (even on a properly functioning Privia). So, my adjustment didn't make any noticeable difference to the black key sound, only the white keys. In the Photo, there are two PCBs visible. The rubber contacts themselves are held by three of these. The further one is corrected to be at the right angle. You can see the tiny difference. But really, it plays like my other Privia that didn't have this problem. This was the most maddening keyboard issue I've encountered yet. It works now though Warning: If you use a material too thick, the key won't work at all or will cut off abruptly. Start small and work up. I got lucky on my first try, by comparing it to a youtube video of Privia 850 action from the side.

I just want to add my experience to this thread. I've played 3 perfectly working privias ( Px860, px160, px 850 again) and one that had this irritating Keboardwide issue of the black keys being uniformly softer than the white keys. I discovered only that the issue wasn't in the keys themselves (I swapped out keys), nor in the brains of the keyboard, but instead somewhere in the entire plastic piece that holds the action/hammers/sensors etc. I swapped out a working plastic key bed with everything attached , with the one that worked fine, and the keyboards switched issues. I'm reluctant to pay a bench fee but I'd really love to find out what in the world the problem is. It's not a difference in sampling or whatever, as some people have suggested. It's some problem, perhaps in the hammers, of perhaps in the off-white plastic piece itself that holds the action. If I ever figure it out I'll try and post it to every post where I see this issue. Right now I suspect it is some kind of defective main keybed in a tiny batch of privias due to poor quality control. The shame is that very inexperienced players won't detect it. It's also less noticeable at lower volumes. So if you are in a rush like I was, you can end up with a lemon from someone who didn't know the difference, that's out of warranty.

Did any liquid or particles of whatever fell on it get into the keyboard? That would be the first thing I'd check

Not knowing a single thing about your knowledge, the only thing I can think is to check if it's a mono 1/4" to 1/8" adapter (one strip instead of two on the plug), then it might not work.

I just opened a px-150 and took out the key action. In my opinion, if you are electrically savvy or have messed around with electronics and arduinos and the like , you don't need a schematic or service manual if you're just replacing the main board. All the boards in the Casios I've owned have kind of standard clips and such.

For the record I think the "classic" sound option is smoother in turns of dynamic range. The Grand default thing has an unnatural spike at a certain point.

Update to everyone. Thanks for chiming in. With patience, I nabbed a px-150 for $150 . I took out the entire keybed, swapped it into the Px-850 and the 850 works perfectly now!!! Before the key action swap, I had ruled out - the keys, any felt issues, and I think the contacts. Now, I have a px-150 with the same problem but I intend to keep tinkering until I figure out what on earth is going on. All told I learned a heck of a lot, especially that the key actions in px 150 , 350, and 850 are 100 percent swappable IF You are a de facto tech. The lay person has no chance with this operation.

The white keys on mine are all labeled 21. a21 b21 c21 etc. I'm curious were all of your white keys labeled 22? I see in the middle they are. Thanks!

Ditto on taking lots of pictures. I also used a magnet board to group the screws together, in order of the disassembly.

I also live in a 100+ year old noisy apt, and could feel my keys thumping literally on the floor in my feet, but a little styrofoam underneath and viola - no longer. But yeah that neprene thing looks thinner. Good thing is you can test different solutions but putting your feet on the carpet near the base, and playing fast/heavy. It's amazing what some absorption can do

I experience this as well, but only on the white keys.

Hey Brad after further tests... I don't think the headphones are broken - it's just a equal panning from right to left. Really not how it sounds sitting in front of a piano where resonance is a huge centering factor. I stand by my comment about binaural samples being superior though that wasn't what this reviewer was asking