Rig Boot loop

Hi,

I have a mining rig issue.

I have a 6x Sapphire Nitro 5700 XT and when I plug all 6 cards the rig shuts off after 1 minute and restarts; however with 5 cards it runs ok (its been on for a few days now).

Im not sure if this is a hive issue or a defective hardware, I have swap cards and risers and this still happens.

The specs:

Motherboard: MSI z170A G45
PSU: Corsair AX1200i
Ram: 8GB (2x 4GBs)
Cards: 6x Sapphire Nitro plus 5700 XT
Risers: 2x ver 009, 3x ver 006, 1x ver004
Power: 89w per card (one of the cards run at 85w)

I would like to mention that the motherboard threw some issues at the early stage and as it only accepted 4 cards but after some bios tweaks, 6 cards now show up.

I also did see some posts where people have tripping off issue with the AX1200i.

Has anyone experienced this? Could this be a motherboard, Riser or PSU issue or HiveOS showing high power draw at some point.