07-25-2018 03:41 PM
I unplugged the cable to move my ultrabook, plugged it back in and now the connection with the external monitor is completely dead and won't come back, any chance its something other than the USB C port being broken? It worked fine for 48 hours.
07-26-2018 06:23 AM
Seriously not cool, I spend an hour messing around, connecting and disconnecting things and reinstalling drivers, still doesnt work so remove the cable and go to sleep then in the morining it starts working normally again for no reason at all. What sort of technology is this? Unbelieveable.
07-26-2018 06:42 AM - edited 07-26-2018 06:45 AM
Might need a little more information. Make and model of the adapter. Type of connection (HDMI, VGA, etc) and make and model of the external display. If it's HDMI, it could be as simple as unplugging the display's power for a minute, then plugging it back in. HDMI handshaking is often problematic.
Other possible issues: fried adapter, you accidentally hit the function key that turns the external monitor off while moving the computer, Windows or your graphics adapter didn't properly detect the reconnect or a number of other things.
Make sure all of your drivers are the very latest, as well as the BIOS. Check to see if the adapter mfgr has new drivers. Run a Lenovo Vantage Hardware Scan. If you still suspect things are amiss with the USB-C circuitry, look for warning flags in Device Manager and check your Windows System Logs using Event Viewer.
(written while you were making your second post, which I didn't see until after posting this, not that it changes much of what I said. "Fried adapter" is about all that's now ruled out).
07-26-2018 08:01 AM - edited 07-26-2018 08:05 AM
Thank you for the post. I'm not a computer noob, all I did was unplug the cable and move the location of the laptop before plugging it back in which caused a failure in the USB communication between the laptop and the monitor for at least several hours, despite me resetting numerous hardware and software variables over that period.
Having given up and looked up the number for Lenovo support I left the system overnight and just plugged the cable in and for no reason it worked straight away. The only variables that could have changed during that period were the temperature of the system and possibly static buildup? I have no idea but I'm now very concerned that the system will suddenly stop working again.
It's a brand new premium cable and a modern, premium television and I can't see a good reason why the external monitor system would stop working for a few hours completely, after the cable was unplugged, and then start working again after the passage of a short amount of time.
Lenovo Yoga 900s > Premium USB C to HDMI 2.0 Cable > Sony Bravia TV
Just wondering whether I should flag an issue before the warranty expires.