Small Form Factor build

Okay so a year on from my first pc build I have problems, firstly the case sucks it's loud and the RGB fans are weird and don't allow you to both control fan speed and colour at the same time. It's also pretty big. Secondly I have recently encountered an issue where it will randomly not crash just black screen and GPU fans will go full speed. The GPU has been tested on other machines and is fully functional and it has been reseated and the ram also works. So it's probably a board issue or a PSU problem - strange as it's either the board or the PSU. So if I am replacing the board I may as well replace the case too.

I'm looking for suggestions on boards and cases and also perhaps some wisdom on the issue I am having. Thanks my specs are below.

Budget £150 - £200

CPU - Ryzen 5 7600 Board Gigabyte B650M D3HP AX GPU - RTX 4070 SUPER Case - Antec AX27 RGB Elite ATX Power supply - THE RAM - 2X16 DDR5 crucial ram