If your box will not power on, this is an issue with your Softbox power supply or power cable.
1. If you have another Softbox with a matching power cable you could try that power cable to see if fixes your issue.
Go here to purchase a new power cable:
Softbox 3:
Softbox Buzz:
You may be able to to just plug your softbox buzz directly into a USB port on your TV- So try that first. If not any modern USB power cell phone charger could work if it is 10 watts or higher. This is one we recommend: https://a.co/d/0UCaumV
Softbox Go(White):
This is one we recommend: https://a.co/d/2yYyCzf
Softbox Go(black)
This is one we recommend: https://a.co/d/ixbwvOK
Softbox X or Softbox Pro:
This is one we recommend: https://a.co/d/2xYi5GW
If the new power cord does not fix this then you need a new box.