Casio CTK 3500 (electronic keyboard) doesn't turn on

[gigglyrip]

I've Casio CTK 3500, which I purchased in 2019. It was working fine till last week but suddenly it stopped turning on. I'm not sure what happened as nothing has changed. I'm using the same old adapter that used to work, using the same generic pedal that I've always used.

The bars on LCD blink while pressing the power button but as soon as I release the power button, it goes off.

I also checked my adapter using a multimeter (no idea what I'm doing here, just followed some youtube video), and the output was 9.5V - 9.6V, so I think the adapter is okay. Is there any hard reset key that I'm unaware of?

I also cleaned everything inside with a brush along with alcohol. The power button looks fine to me, no circuit break or anything suspicious (Although, I don't know much so don't take my word for it, please check the images).

How can I fix it?
Please help me fix it.

Motherboard: Image of the motherboard

Current behavior:

[barshatriplee]

If no sound is coming out, perhaps there is something wrong with the speaker. I think it's better to contact the seller for an after-sales service.

[gigglyrip]

It doesn't turn on, not really about no sound.

[Nusa]

You can eliminate the power adapter as a problem by trying the unit on batteries. If the problem remains, it's not the power adapter. If the problem goes away, it IS the power adapter.

[gigglyrip]

Nope, I checked with batteries. That didn't fix it. It's basically the same, just blinks at the click of power button.

[LinuxHata]

Well if there's blink, that means that at least power button watchdog is ok, but when circuit starts, something is wrong at power line, so protection kicks in and turns off the voltage regulator. A thermal camera would help a lot in finding which component is misbehaving.

[gigglyrip]

I'll take it for repair. Don't think it can be fixed by me with zero electronics knowledge. Thanks for your suggestion though.