2yo Blackshark V2 Pro won't turn on or charge - Slow red flashing light. 3.5mm output but no mic input via jack.

Hi, can I get some help with my headset pls?

My 2 year old Blackshark V2 Pro won't turn on or charge: there’s a slow red flashing charging light that never turns green.

Tried updating firmware, but I’m up to date; the firmware util detects the headset via USB, but Synapse won’t.

3.5mm audio output works as normal - but that includes no mic input, which I need from this.

Thanks.