Galaxy A51 got stuck at startup (Samsung galaxy a51 logo) .

[userhQXu63LEDP]

I opened my WhatsApp and it started to make its backup as per the routine. and suddenly my phone went into start screen that is  (Samsung galaxy a51 logo) and got stuck there.

I'm not able to turn it off or do anything. even I can't do a factory reset it isn't working. I have tried a couple of times by pressing the power button and volume down button but it restarts the phone and again gets stuck at the start (Samsung galaxy a51 logo).

I'm so frustrated at the moment and I don't know what to do. I have tried connecting it to the laptop but it isn't responding there as well. it's behaving very differently yesterday.I kept it on charging and plugged it out after 20 % battery and then turned it on but showed the same logo.

Then I slept and woke up and plugged in the charger without pressing any button and it showed the factory reset screen I selected the 'reboot now' then it started and crossed the initial startup logo and went to the Samsung logo. then again it turned off and went to the same problem. that's all the case. please help me and suggest to me what to do.

thank you very much

[Ekamek]

Try volume up and power button to get into recovery mode. If you know how to flash it, volume down (or up), power button and USB cable to get into download mode. Flashing it with the latest firmware should get you out of this mode if resetting from recovery mode does do it. You can also select safe boot mode from the recovery mode screen to see if it let you get to the screen.

[userhQXu63LEDP]

Hi, thank you for your reply. 

I have tried with the volume up button and power button but it isn't responding to that either.

[Ekamek]

If suggestion from @SmithBoy doesn't work, just let it drain the power and power off. If close to ubreakiFixit store, see if they can fix it for you. Good luck getting it working again.

[SmithBoy]

Hold volume up and power button but take power button off bixby routine first and den wen logo up...keep tappin down til the green android man pops up