Thanks to Lenovo Rep - Andy A. who took time to visit us in (Cleveland, OH) today from Lenovo (Columbus, OH) - Much appriciated!
There are several things to look at, that can possibly fix the issue:
- If the RED LED on the top or the Docks power button is going to sleep, it flashes very fast, then slows down to a periodic glow – this means that the unit is entering SLEEP MODE when its flashing rapidly. Likewise, to remove from SLEEP MODE, you tap the power button on Dock or Laptop 1x to remove from SLEEP MODE. It’s possible you just need to tap the power button 1x to wake up the PC.
- When a Laptop is attached to a NEW Dock for the first time you will see a pop-up stating "NEW THUNDERBOLT devices have been attached" - click OK, Yes, Select "ALWAYS CONNECT".
- X1C5/Thunderbolt 3 dock – we have seen where two separate devices using two separate USB transceivers can slow response. If possible try a Unified Transceiver (single USB Transceiver) Using this type of device allows 1 transceiver for purpose of using both devices such as a mouse and keyboard vs. having two separate transceivers – one for a mouse, one for a keyboard) – this speeds up reaction time apparently (Win7 more noticable due to slow response, Win10 less noticable due to faster response).
- Check BIOS > Config > Thunderbolt 3 Menu should be set like this (all default):
- Wake by Thunderbolt 3 = Enabled
- Security Level = User Authority
- Support in Preboot Environment:
- Thunderbolt Device = Disabled
- USB Device = Disabled
- I had previously had ENABLED both PRE-BOOT Environment as an attempt to solve the issue – lesson: (Leave it as Default / Disabled).
(Verify BIOS, Thunderbolt firmware and software are updated on X1C5 and older models):
- Update BIOS…
- Update Thunderbolt Firmware…
- Update Thunderbolt Software…
X1C4/Dock1+ - Keyboard and mouse seemed to not wake up after sleep.
- Run System Update from https://pcsupport.lenovo.com (where the system detects what needs updated vs. what’s installed) the Hotkey update was installed and proved to be the fix or solution in this case.
X1C5 / Thunderbolt 3 Dock – ALWAYS USE a 135w power supply and also when a Laptop is attached to a NEW or different Dock for the first time you will see a pop-up stating "NEW THUNDERBOLT devices have been attached" - click OK, Yes, Select "ALWAYS CONNECT".
Also see Lenovo's T-shooting Guide: