Ps4 no audio though hdmi

I have a ps4 original that everything works fine on apart from there’s no audio, except through the controller speaker.

Does anyone have any idea what it could be and if I can fix it. I’ve been repairing ps1, 2 and a little bit on the ps3’s but this is the first ps4 I’ve got hold of to try a repair on. Apart from a ps4 pro which just had a bug short the power supply board.
Noone locally seems to repair consoles so people just throw them out so I decided I’d start giving it a go.

Many thanks for any help.

I initialized with a flash drive when I had this on one unit and it fixed it

Thanks for the input. Tried that already tho. Made no difference unfortunately.