DisplayPort not working - help!

Big Chris · 20 Jun 2017 at 20:24

I've got a 5 year old Lenovo Thinkpad T410 with DisplayPort and VGA outputs. I've recently bought a new Dell monitor that takes HDMI, DisplayPort or mini-DisplayPort inputs. I've plugged the laptop into it using Displayport to Disaplyport, and Displayport to mini-DisplayPort (both cables brand new and came with the monitor) but there's no sign of life. The monitor just tells me there's no signal from my device on either input. Strangely if I remove the cable from the laptop then plug it back in, the monitor gets some sort of kick as it then displays the 'no connection' message again immediately.

I've never used the DisplayPort output on the laptop before so it could just be knackered, is there any way of telling? I've checked the onboard graphics drivers are up to date, and I'm told by Windows and the Lenovo website that they are, and I've been through all the settings in the Intel(R) Graphics software too but can't find anything that refers to DisplayPort.

Any ideas? Or is it time for a new laptop?

Big Chris · 21 Jun 2017 at 07:50

I've also tried a Lenovo M58 desktop PC I have via DisplayPort and that has the same issue. Again, I've never used the DisplayPort output on the PC so I'm unsure if I need to enable it somewhere, but I've checked everywhere I can think of and can't see any options.

lude1962 · 21 Jun 2017 at 09:42

is there function keys to switch to external display?

Big Chris · 21 Jun 2017 at 09:46

Not that I'm aware of, but I'll check again. I've tried Windows+P and chosen all the available options - duplicate/extend/second screen only - but none of them work. I've used the laptop via VGA millions of times and that works fine.

Big Chris · 21 Jun 2017 at 19:15

There is a hotkey for changing the display but it doesn't work, the laptop screen just goes blank for a second then comes back on.

The DP output on the laptop is definitely doing something, as each time I unplug then plug either the DP or the Mini DP cable back into it, the monitor pops a message saying no device detected on DP or Mini DP connection - depending on which cable I've plugged in.

Could it be that the version of DP on the laptop is too old or something?

Big Chris · 22 Jun 2017 at 21:03

Any ideas anyone? I know you guys like a challenge...

Should DisplayPort work in the same that VGA does, in that when I plug the laptop into a VGA monitor and close the lid it just jumps over?

Big Chris · 23 Jun 2017 at 19:09

I've managed to make some minor progress... there's a setting in BIOS for Primary Boot Display, I've set this to DisaplyPort, closed the laptop lid and started the laptop and it shows the initial ThinkPad post screen followed by the Windows 10 logo with egg-timer (spinning circle of dots) on the monitor as Windows boots up, but as soon as it gets to the Windows login screen the monitor goes blank and says no signal then it drops back to the laptop screen. After that, no amount of Windows+P or Fn+F7 or any settings in the Intel software will get it back on the monitor. Device Manager and Intel don't recognise there's a second monitor either still.