Even without powerlights, can you hear any clicking or faint buzzing when you apply the mains. I've had a few Cine 7s fail in the switch mode power supply.
There are two glass fuses which are worth checking you will need to pull the power supply tray forwards to get to them.
There are two cross head screws on the front grill under the lenses undo these and slide the power supply tray out a few inches. Don't take it all they way out they are tricky to put back and you may disturb a few key components.
You can take the power supply out but you have about 8 little yellow multipin connectors (all should be colour marked or are differnt lengths) the EHT, Focus and earth leads and the EHT feed back line.