USB-C Docks and odd power issues - sanity check

[pete]

In the main part of School A, we use USB-C docks without any problems.

 

In a small part of SchoolA across a shared access road and connected to a different electrical feed, docks are unreliable and screens may drop out without any rhyme or reason.

 

In School B, a test dock is also unreliable and screens may drop out without any rhyme or reason. School B is a primary school long overdue an electrical refit, but the power supply is reasonably reliable.

 

Having done everything but put the monitors + docks on UPS, I think it's the electrical supply at School A and I don't have enough data at School B yet.

 

Any other suggestions?

 

Background:

 

• Affects equipment at 2 school sites
  
• Affects Anker and Startech docks (firmware updated)
  
• Dedicated 65w power supplies for the docks (tested without too)
  
• Same laptops and firmware versions at each school
  
• Same monitors used at each site.
  
• Same USB-C and HDMI cables used at each site.
  
• Hardware that didn't work does work if moved to the main part of School A's site. (I'm using one to write this)
  
• No sources of electrical/radio interference (that we're aware of)
  

 

Dock has the following connected:

 

• Ethernet
  
• 2x 24" Iiyama monitors via HDMI
  
• USB mouse wireless receiver
  

[psydii]

Do laptops travel between sites?

[pete]

SLT, finance and IT do, but they don't tend to take a dock (usually WiFi and USB-C portable screen for finance) as there aren't any "spare" desks with mounted monitors.

 

I take a dock on occasion if I'll be there a while, need a couple of screens and can use a classroom display TV as a second screen. But I don't get the flickering.

 

A laptop experiencing problems can be moved to School A's main site, connected to an identical setup and work for months without any flickering.