S500wi Interactive Projector - USB-A port no longer powers external device

We have 4 Dell s500wi Interactive Projectors. We have a Microsoft Wireless Display Adapter (WDA) plugged into the HDMI port of each. The USB to power the WDA is plugged into the USB-A port of the s500wi. This has been working fine for 5 months. Recently one of the projectors USB-A port has gone dead, i.e. it no longer powers the WDA. The other projectors are still working.

Is the USB-A port power a configurable item? Is there a fuse for it or some other way to reset it? Is it a serviceable/replaceable part?

Thanks for any help.