I tried learning last year.. damn susah when no time dedicated on it.

eh jap lu ke yang beli keyboard haritu ke orang lain, macam dah lama gila
C,D,G, Em je.. major keys senang semua main white keys je
ko guna shape chord C major tu naik kan satu note dapat lah chord C, Dm, Em, F, G, Am, Bdim, C
oo tak pernah try yang piano yang besar2 lagi
you classicaly trained?

either capacitor rosak or ur AC transponder rosak...

Can be many things lah. You have to dismantle and check. Speaker problem, cable problem, capacitor, etc. If you have no skills to repair, buang jer.

One simple way to test a bit is to output to external speakers...if no problem, means only the internal speaker circuitry is haywire. If same, means a lot of things could be wrong.

I dunno if music store actually knows how to fix anything electronics. Most knows how to sell only. Same thing, you don't take your TV back to Harvey Norman and expect them know how to fix.

bawak je...no point fix urself later whole thing rosak

ambik digital piano lah bunyi lagi sedap dari cheap keyboard tu
cari yang boleh support midi nanti dah bosan boleh try pakai DAW lagi shiok  boleh try instrument lain 
what piano you use? thinking of getting an upright but sked maintenance mahal

Got cat

If got cat piss all over it maybe

Kek

Ah I see. Just get a pedal. That'll make things easier.
TS sounds like he's far from that level anyway. Barely near chord progression

random buzzing noise or constant high pitch noise?