USB-C to C DP/Charging/Peripheral Issues

CrowTheRobot · October 21, 2021

Looking for a little help with troubleshooting.

I work for a school district where we've started deploying special Chromebooks for teachers. They're Acer Spin 713s with 10th Gen Core i5s, 256 GB of onboard storage, and 16 GB of RAM. The intention was to deploy them with Dell monitors that support DisplayPort signal, charging, and hub use through USB-C, with the intention that with a monitor, keyboard, and mouse, the Chromebooks could be primary workstations to supplement large touchscreen boards being widely deployed. However, we're running into problems where the monitors will seem to lose display signal randomly and multiple times each day, momentarily shifting the content back to the Chromebooks before the signal returns and all windows shift to where they are on each screen. We've been trying to isolate which side of things is the culprit, but nothing seems consistent. In some cases, swapping the Chromebooks entirely seems to resolve the issues, which would seem to point to the Chromebooks themselves, but we've seen cases where a Chromebook won't show this issue on an older model monitor with the same configuration, but as soon as it's plugged into the models we heavily sourced for this, the problem starts almost immediately.

The only lead I feel like we've possibly found is that the Chromebooks have C ports rated as USB 3.1 Gen 1 while the monitors have Gen 2 ports, and the stickied thread here about cables and adapters suggests a 10Gbps cable for DisplayPort thru C (and our cables are most likely 5 Gbps), but that still doesn't explain how the issues seem to be non-existent on older monitors with presumably the same or possibly slower C ports.

Any thoughts? Any clarifications needed?