Casio Privia PX410R

[gc.cipriani]

Good morning,

I must to repair (for tyhe school of my son) a digital keyboards (Casio privia PX410R). Where I can found the schematic/electronic diagram ? The keyboard had a problem with the volume (is always low and if a turn the potentiometer don't change).

Somebody can to help me ?

Best regards

Giulio

[Jazz P Bass]

I cannot locate a service manual for that model.

What is wrong with the keyboard?

[gc.cipriani]

The problem is this: the volume don't change. The level is very low. If I change the set point with the potentiomete, the volume don't change (I hear something if I go near the loudspeakers). I haven't connected an external amplifier but at school (the keyboard is of the school of my son) this test it's been done with the same result. I think that the problem can to be in the output amplifier. I need the diagram for to avoid loss of time. I want to check also the output connectors (two jacks) because on another keyboard that I have repaired (of another productor) one of this was been damaged and the signal do not pass trough it. I think that the problem can be the same but, for check it, the electric diagram is very useful !!!
bye
Giulio

[Jazz P Bass]

Have you tried connecting a headphone at the 'headphone' jack?

Have you tried going into the 'microphone' input. This has a separate level control.

[gc.cipriani]

I've connected the headphone but I don't hear nothing. I will try with the mic (it's possible that the problem is in the out section of keyboard). I want also to verify accurately the jack out (many young students uses the keyboard and it's possible that they have damaged the connectors. These jack with many internal switches are very problematic).
I will try, with the oscilloscope, of verify the signal point by point (whitout diagram is not easy but I haven't other solutions)

[gc.cipriani]

The connectors are ok. The problem (I think) is in the volume regulator that is a strange component. It'snt a normal potentiometer. Initially I think tyhat is an encoder (for the 5 pins) but on the audio card (go directly to this) there aren't microprocessor or decoder circuits. Can to be a stereo potentiometer ??? I send here a photo.

[Jazz P Bass]

That appears to a '3 pin' potentiometer.
The other two legs are for support.

Do you have a signal going into that board?

[gc.cipriani]

It's a 5 pins potentiometer.... I've found the data sheet... It's an ALPS potentiometer. I think that can to be this: RK09K/RK09D Series - Basic information
I've send a request to ALPS for info. I've tested the potentiometer with a tester and the resistive value don't change (the cursor is damaged?). If I found the potentiometer ok. Otherwise I can to use a stereo potentiometer with a similar connection. I think that the problem is this (mechanical problem)

p.s. the 5 pins potentiometer for me is a big surprise ! I know the standard and stereo potentiometer... but I haven't never seen potentiometer with 5 pins (two pins in common mode)

[g1]

That is a dual (stereo) stacked pot. The 2 pins in the top layer are the 2 wipers.

[Enzo]

And flip the board over and see where the traces go. 5 legs sounds like a stereo pot to me too.

Before you decide the pot is bad, scope the signal reaching it. If the signal is super weak getting to that control then the control can;t make it louder.

[doctor]

If you really need to replace the potentiometer, you can order it from Mouser.
As a rule Casio uses 5KOhm (Mouser part number 688-RK09K12CKA502).
You need only to check whether this 30mm shaft length will be suitable.

[gc.cipriani]

It's the same (as productor). My potentiometer is another (shaft of 25 mm) but it's an ALPS !
Thanks !!!
I will replace it asap !! I can't order a single piece but I will search somebody that can to order it for me

[guitardad]

It's the same (as productor). My potentiometer is another (shaft of 25 mm) but it's an ALPS !
Thanks !!!
I will replace it asap !! I can't order a single piece but I will search somebody that can to order it for me

Its the pot! I just fixed one last month on a PX110. The tab pin to the rotary shaft breaks off. Pot opens and feels loose.

You can't find that pot anywhere. Casio says not in stock.

What I did was find a similar pot and then removed the plastic shaft from new one (10k pot) and put it on the orig 5K pot.

It's also a strange layout for the pins so be cautious of replacements.

This should work for Eu dealer
SOUNDCRAFT M ALPS ROTARY POTENTIOMETER 5-PIN 10K Rotary Potentiometers dm1248

For USA
http://www.mouser.com/ProductDetail/...jc3XqKL3wnY%3d

Or this one like I ordered. It's Hz mount, and 10K but I only needed the shaft. It was a couple mm longer, but I was able to cut it down easily with a util knife. I just removed the good plastic shaft and put that in the old one. Worked perfectly. about $4 w shipping.

https://www.westfloridacomponents.co...9K12A0A5F.html

[gc.cipriani]

I haven't found the correct pot. The delivery time is of 8-10 weeks !!!!
I've mounted another pot and I have used the same configuration (a 10k log pot).
Now all works correctly (with the volume).
But I have another BIG problem.
When I start the keyboard and I play a note, I hear the note that change. If a play for example a central DO, i hear a "sweep" from lower notes to higher notes and stop to a note different and don't change. In the specific case I switch on the keyboard and play DO. I hear a note that start with a SI and sweep to a RE and remain RE. If I play the DO, i hear a RE (tested with a real piano). All the notes are shifted of +1.
Can you help me? How I can to solve this problem?
Giulio

[Enzo]

Check to see if you have a transpose function turned on. Also check to see if "portamento" is turned on. If so, turn them off.