Troubleshooting multiple monitors on a Surface Dock 2 (Surface Pro 7)

I had the same issue with my Surface Laptop 4, Surface Dock 2 and 2 Dell 27 inch monitors (S2721NX) that kept intermittently going blank showing hdmi signal not detected. My connection was monitor hdmi to usb-c adapter to Surface Dock 2 display port for each monitor. I spoke with a best buy guy Greg who recommended going hdmi to hdmi in a dock, no adapters, no dongles and something about passive cables. This is what I ended up getting and after installing the software I am back up and running. I returned all my cables and adapters. Going to return the Surface dock 2 next. What a pain but at least it's resolved.

https://www.bestbuy.com/site/j5create-usb-type-c-triple-display-docking-station/6357396.p?skuId=6357396

I feel your pain.

I bought four different 'Active' USBC-HDMI/DIsplayPort adapters/cables.

The only one to consistently work was the Microsoft one at AUD$65 each.

Maybe they're borrowing sales tactics from Apple?

Right,

I thought I'd post this as a current update to this widely reported issue.

I too, whilst researching for my firm, encountered this issue using a multiple number of configurations.

What we tested was Surface Pro 5, 6 7 and 7+ with:

Single 28" Benq 4K monitor (up to 60Hz)

Single iIlyama 24" Full HD

Dual iIlyama 24" Full HD

Single LG UltraWide 29" and 32" monitors

An amazon recommended USB-C to HDMI Rated at 4K@60Hz

and another mid range brand at same spec

We had exactly the same issues in that it only affects 7th Gen Surface Pros and above with fast charging capabilities (and similar equivalent models like the surface book 3). Blank monitors, not enough power warnings, very low resolutions when a monitor did show.

We tried all manor of cables too but as a hail mary i investigated the actual cable specs a bit deeper.

It turns out, to get full compatibility you can only use DP1.2 or DP1.4 (or higher i presume in future) USB-C to HDMI or DP cables.

Be very weary of sellers cable specs and look for this particular specification. Do not base your purchase on the common description headlines of 4K @ 60Hz, even if you intend to use with standard HD screens.

I dont know the ins and outs of cabke specs but i'm lead to believe the DP1.2 and above spec cables have a particular power carrying rating that even though not used to power the screens, is vital to using the monitor ports and will causes issues with these docks (hence the low power warnings).

Annnnd the most recent Windows update results in yet again loss of a monitor after reboot. I've had my monitors set to NEVER sleep, and just use the screen saver function so that I minimize how often I have to go through this ordeal ... until MS decides it needs to update and then it starts all over.

The 'trick' only works some of the time though, which is what is so maddening about all of this. If the problem had a one time fix it wouldn't be such an issue, but it's "whack a mole" in that every time I reboot, or the damn thing decides to reboot on it's own, the problem starts all over again. Just yesterday the solution was to go through the Win+Ctrl+Shift+B process no less than 5 times while one or the other monitor worked but the other didn't and then FINALLY they both worked. Quite simply this product sucks, but I can't afford the alternative which is to completely abandon it. *&^%*&-you MS - fix this mess.