I would like to purchase the actual instruction manual for my CASIO keyboard CTK531. I am not interested in the download as i cannot see it clearly. Thank you

A Casio Keyboard Service Centre is the best idea.

Casio Ctk-900 Service Manual - CTK900 - HelpOwl.com

https://www.helpowl.com > Casio > CTK900 > Research
Casio Ctk-900 Service Manual - CTK900 ... Get support for Casio CTK900 ... Our system has returned the following pages from the Casio CTK900 data we have on ...

Manual Casio CTK-900 (page 1 of 108) (English) - Libble.eu

https://www.libble.eu > ... > Casio > CTK-900
View and download the Manual of Casio CTK-900 Keyboard (page 1 of 108) (English). ... authorized CASIO Service Provider. AC Adaptor

Turning it on and off and on again initializes the keyboard settings. Page EN10 in the manual make that clear. The manual also has a troubleshooting section in the back. https://support.casio.com/en/manual/manualfile.php?cid=008001061

https://ourpastimes.com/how-to-troubleshoot-a-casio-piano-keyboard-12352821.html

There is no such model.
If you are referring to CT-615, you can purchase a PDF copy of manual from ebay

http://www.ebay.com.au/itm/Casio-CT615-Keyboard-Users-Owners-Manual-CTK-615-/200932122034

you nearest casio dealer may have one in the back of the store,
many buyers don't want/need the manuals so some stores hold on to them for such occassions

Check for videos on YouTube. Also check for user's BLOGs for the Casio using Google. here usually isn't enough market for people to write 101 books as the technology and models change so fast.

Best way is to just dig in and try stuff and self-discovery results in learning stuff that sticks with you.

Page E11 of your manual.

If you don't have the manual, download it here for the PX300:

http://www.manualnguide.com/download/manual-guide/casio-privia-px-300-digital-piano-users-manual.html

Note... other models will be similar in method for the metronome.

Unfortunately the adapter jacks are a bit of a weak point on many keyboards but it is quite seldom the jack socket itself that is at fault.
Often the sockets are soldered directly on to the printed circuit board and are prone to either one of the soldered legs breaking, or even the circuit board itself cracking around the jack socket. 
Whilst it is generally possible, with care, to resolder a broken leg on the socket if the actual circuit board has cracked the whole board will have to be replaced.
If the actual jack socket itself is damaged it should be possible to snip through the legs and remove it before soldering a new one on to the stumps of the old legs. this is likely to prove easier than trying to solder directly onto the circuit board, unless this is something that you are experienced at doing.

Apparently you can purchase a full service manual for the Casio WK-1200 here for a modest price but I have not used this source myself so cannot vouch for how good it might be.http://www.tradebit.com/filedetail.php/2084335-repair-manual-casio-wk-1200-electronic-keyboard

Your manual should give you the info you need. Here is a link:http://www.casio-intl.com/emi/standard/ctk810.html Go to the bottom for info on Vista drivers. The other systems drivers are on the bundeled CDRom that came with your purchase. If you don't have it ,try here:http://support.casio.com/download.php?cid=008&pid=340&rgn=5 Hope this helps.

Hi,

You can download the complete instruction manual in PDF format by clicking this link.

• You'll require Adobe PDF Reader installed on your computer to view the manual. If it is not already installed on your computer, download it free from: http://get.adobe.com/reader/

Hope this solves your problem. Thanks for using FixYa.

http://safemanuals.com/user-guide-instructions-owner-manual/CASIO/CA-100-_E