Car completely dead

[Chicken little]

We have a 3008 which started displaying bpga issues, Bpga replaced end of last year, then randomly the car is completely dead, no response from stop start button, literally nothing. It's like it's completely shut down, battery is fine (replaced November) and also reading good voltage. Scanned and bringing up multiple faults but because the ignition won't turn on they are stuck finding what is causing the issue. Bpga replaced again in case it was a faulty one, car started for a split second and blew the relay. Continuity tests all good so shouldn't be a broken wire, fuses all good. Garage is at a complete loss, unless we start guessing if its a random bcm and replacing and coding not sure what else to do, it's like chasing a ghost.....

[wheeler]

When you say completely dead do you mean nothing at all? Do the hazard lights switch on if you press the hazard switch?
Have the main power supplies & earths been checked & confirmed good?
Have all fuses been checked including the maxi fuses?

[Chicken little]

The door unlocks and the light flashes on wing mirrors but don't open, when you press the stop start to get the dash to light up absolutely nothing, parking break is stuck on, steering wheel is locked, economy mode lights up ( only because its been stood) but when they put the jump pack on the battery it reads correctly but because the ignition won't turn on the scanner cannot complete the scan. Absolutely no response from thestop/start ignition.

[Chicken little]

All fuses checked, continuity test shows no breaks in any wiring

[Arkis]

Have you tried disconnecting the battery for an hour? Doing BSI reset? Does 3008 have main fuses at the battery (little plastic box in front of or on top of battery)? Did you check those?

Edit: Yeah, BPGA is that "fuse box" I was reffering to.