T420 and 4337 Dock

[Scorpion8]

Just picked up 2 4337 docks to use with my T420 in several locations, and neither seems to display a video signal out of the DP to a monitor, even if the laptop is set to use only the outboard monitor. I'm using a 95W Lenovo power brick to the dock. Is there a BIOS setting I need to change or anything else that could be causing this? It occurs with both 4337 docks. TIA.

[Scorpion8]

I set the BIOS "display" to <Digital+dock1> (think that's what it said) for startup and on the 3rd reboot it worked. Huh. Now if the laptop isn't on the dock, will it default to the laptop native display?

[dr_st]

Yes

[atagunov]

Weird.. both of my T520 and my X220 just work in my 4337 docks; think disassembled X230 worked too

[UMPC2024]

Just picked up 2 4337 docks to use with my T420 in several locations, and neither seems to display a video signal out of the DP to a monitor, even if the laptop is set to use only the outboard monitor. I'm using a 95W Lenovo power brick to the dock. Is there a BIOS setting I need to change or anything else that could be causing this? It occurs with both 4337 docks. TIA.

95W? I thought for the T420, there was the 65W, 90W, 135W.

[cadillacmike68]

Probably just a typo on the wattage.

[Scorpion8]

95W? I thought for the T420, there was the 65W, 90W, 135W.

Yea, picky, typing too fast. 90W brick.

[UMPC2024]

No, I just wanted to make sure that it wasn't a counterfeit one because that could cause problems.

[axur-delmeria]

You may need to push down the T420 to the dock a little bit. l've experienced this on my X220 with 4337 dock.