A1708 Weird boot behaviour

[dome1]

Hello!

This is my first post here.

Recently i repaired my costumers a1708, 820-00875. Where U3200 was in short, it got replaced, device started working again without problems. Fastforward 4 months and it has problems with booting.

Sometimes it shows apple logo, is stuck, then shows a crash screen
Sometimes it just boots normally

It wont allow me boot externaly, Tried 3 diffrent osx, Bigsur, Monterey, Ventura.

From what i gather i assume bios is corrupted, but what programmer do i use? where do i begin? Any help is welcome

@Edit

Already tried diffrent internal ssd, the smc/pram reset.

[Adogabriel100]

Re: A1708 Weird boot behaviour

Did u already try Command + R? re-install system via online? secure boot on this macbook is activated i suppose, that's why dont allow u to boot an external HDD?

if you are pressing Command + R and does not get you in the recovery menu try this: plug in an external HDD with diferent mac os installers and try again Command + R.