Hi , I`m Jack
Perhaps i can help you with this .
The display is adjustable in 3 increments , look on the front panel between bluetooth and display you will see DIMMER press it a few times to change the brightness
You mean the button has no effect whatsoever ??
How did you get to see the 60% level ?
The display is saying 60% all the time or when you press the dimmer button ?
press it repeatedly , not only once
I`m sorry but something came up and i will have to opt out now.
You don`t have to do anything , your question will be reposted for other techs. to see and jump in.Please just standby and someone should be with you shortly .PS. DO NOT rate or it will hinder the repost .