Casio ct 636 e-piano LOW volume on all keys and instruments ??? Dale

No you can't as our PROPER Expert Cindy says.

Casio Ct-636 does not support any sustain pedals.Amazon.comhttps://www.amazon.com > ask > questions
A: Casio Ct-636 does not support any sustain pedals.

The other 'Contributor' probably saw this

CT-S1000V - SupportCasio https://support.casio.com > manualPDF

This Digital Keyboard does not come with a pedal unit. • You can use the PEDAL1 jack to connect an optional (SP-3, SP-20) sustain pedal. You can use the.

Help in the link, but you may have a sticky key on that reed instrument.

lots here
https://www.google.com/search?q=casio+ctk-574+factory+reset

A video here

Try this first with the piano off, run the control from stop to stop rapidly several times. The object is to clean off any dust deposits and shine the contacts inside the pot. If the pot is not damaged beyond repair, then this should fix it.

Difficult to find, but there is a seller on Ebay who has one Casio CT 647 CT 648 Digital Piano Keyboard Owner User Manual Booklet

Also, in addition to more info I need; look on p 91 of the online owner's manual linked below. Pay attention to Sounds and Effects, the first section therein. Follow the directions closely, esp., read pp. 26, 83, and 86 which are referenced for detailed help w/ sound issues. TECHNICS SX PR305 Manual Page 91

You ay have to edit a rhythm and save it as a "user defined rhythm". During editing the volume of each part can be defined with vol. level ranging from 0-127.

Please read the manual.
Metronome volume can be easily changed by just holding the metronome button.

It should be a 9vdc at at least 900mA but, I have found with casios that if you don't get the original casio adapter, it will have static sounds in the background. It is called an AD-5, I saw them at bestbuy.

Old reply so hopefully it's fixed. Dust or hair can get through the gaps and land on or near the contacts of the electronic key sensors. To be on the safe side (rather than doing a diy) take it in to the technicians. They'll have it fixed in a jiffy

The problem you're encountering is actually a feature, called stretch tuning. While real pianos are tuned in this way it's meant to sympathise with their natural 'organics' and might sound wrong on a digital instrument. The solution is to turn stretch tuning off. The manual should be able to tell you how.

Beofore you replace it, if it is only scratchy give it a good working by sliding it back and forth a rew dozen times. (if it is a slider type) If you can get some electrical contact cleaner with a thin plastic tube, try squirting that into it and work it again, if that fails, then look at the volume control replacement.