DC power supply QW-MS3010D not working properly

[Dvsr]

Hi. I am electronics hobbyist with low budget so as my bench power supply I have this chinese junk. It is supplying voltage and current but it is unstable and current limiting has never worked. When I set some current limit and start to increase the load the CC light starts to flicker and power supply starts to make hissing/crackling noise and it allows the current to rise above set limit. Now the power supply is making constant noise and the current it supplies keeps jumping.
I am noob in diagnosing and fixing electronic devices so I have no idea where should I start looking. I can't see any physical signs of faults. Some solder joints seemed suspicious and I soldered them better but that didn't make any difference.

I took a video of this power supply under load and I uploaded it on Streamable: https://streamable.com/yb7ygs

Thank you in advance for help and tips! I greatly appreciate it