Aquos Android TV / 4T-C50AN

Simliar topic as below.

TV shows the SHARP Logo, then tries booting (colorful loading display), and then crashes and does this in repeat.

Already tried to factory reset, but results in Error 999.

We contacted Sharp Support, and they only said repair is necessary.

Is this some board exchange which can be done privately? Repair is up to 300$.

60" Aquos won't turn on, stand by flashes one fast, one slow