MikroTik cAP ac constant reboot

Hi there,
I’m looking for help with my MikroTik cAP ac which apparently fell into boot loop after upgrading the RouteOS to the newer (stable) version two days ago.

Effect: Once connected, a green led is activated next to the E1 interface, than blue Power is activated, next green LED next to the user icon (and mode button) is on. After few seconds user led is off, power led is off and E1 led is off. And repeat.

I can’t connect to it neither via ethernet (192.168.88.1) nor winbox. There is no wifi available. I also tried some voodoo with reset button but no luck. Is there any way that I can reset it to the default/factory settings?

many thanks!