Yamaha CP33 Studio Piano won' turn on. Was thinking maybe the power chord overheated but really have no idea

it can be repaired or replaced if the boards are still available
Take it to an authorized service to have it repaired and failing that some shops that repair micro wave ovens have the technical ability to repair items of this nature
may be a good radio technician or radio repair shop could also do the repair as it is basically an electronic ( wireless/radio) that is controlled by keys

look for the common connection of A or Eb keys, lose contact might be the cause

Make sure you follow the steps of the procedure below exactly. Connecting incorrectly can make data
send and receive impossible.
1.
Turn off the digital piano and then start up
your computer.
• Do not start up the music software on your computer
yet

3.
Turn on the digital piano.
• If this is the first time yo
u are connecting the digital
piano to your computer, the driver software required
to send and receive data will be installed on your
computer automatically.
4.
Start up your computer's music software.
5.
Configure the music software settings to
select one of the following as the MIDI device.
CASIO USB-MIDI

Yamaha pianos go through a self test on start up. This could indicate a problem on the main motherboard.

Try a hard reset.

Hold down top C key while turning on.

Wait for it to start up, if it still freezes its time to take it to the repair shop.

It sounds like you have a part overheating and failing, then cooling off and starting again. i would take it into the nearest Yamaha repair facility or contact your local authorized repair to come take a look before it goes out of warranty.

Read about initialization on page 61 of your user manual. This is a factory reset. There are two procedures there. If you don't have the manual download it here:

www.yamaha.com/yamahavgn/.../ypg_525_eng_manual.pdf

Without power to the unit no sound should be generated. Make sure there are no other connections.

MAYBE you have a wall transformer behind it that is buzzing. MANY wall transformers develop buzz.

Another source is flourescent lights and even some of the low voltage halogens have noisy transformers in the base.

the back light is maybe to hot and it not good no more well one side it not

We're talking about audio recording. If so you must conntect your piano by using the L + R outputs with your sound card or mixer line inputs (that's how I do this). USB is ok if you want to use your piano as a master keyboard (MIDI). Another important thing is that you must have an additional application installed called sequencer ( for example Cubase Sx, Sonar...) which will let you store your digital music. I'm not talking about the proper settings of them because it could take a day or so...:)
Overall, you will have to learn a bit about the home studio, home recording techniques. There are tons of informations on web. A great thing is that you can use your CP33 as a master keyboard to control additional virtual instruments (VST) or for example play different piano samples (check Synthogy Ivory). Possibilites are endless!

Regards
Radek