08 No Ready Mode after battery disconnects

Hello! Need help troubleshooting a Gen 2 Prius that wont Ready Mode

Took out the service plug Unbolted negative grounding wire from frame

Tried to remove bolts to HV cage, one is stuck, will need new tool, put it back together.

Reinserted safety plug. Have subsequently checked this several times.

Bolted grounding wire. Slight spark, nothing weird.

Press POWER with brake depressed

Car will only show HV battery display (motsly charged, all blue bars), A/C runs, gas gauge shows one, brake lights work, all in all — seems to be connected to 12v (?), but won’t actually fire/ready mode. Normal (?) clicks from HV when trying to start.

What should I start checking? Thanks!