In config.txt:
* Remove initramfs edid.cpio
* #comment out hdmi_enable_4kp60=1 as this requires more power
If you are using any kind of micro-HDMI adapter, bin it and get a proper micro-HDMI to standard HDMI cable. Or if you are using an Argon case, remove the board from the case and connect it direct to the TV (it uses an adapter, and adapters cause problems). Also try other HDMI ports on the TV (not all are equal).
It was the micro-HDMI adapter. Picked up a proper cable and its working now. Thanks