T450 displayport not detected

[enstain]

I have an issue with the miniDP connection. I use it for an external monitor via miniDP to HDMI connector. It was working fine until I moved my laptop last weekend. Now the laptop does not detect that it even has a DP. Only VGA output is available.

I have updated everything from the Lenovo support center and tired re-instaling video drivers. No changes so far. Any ideas?

the graphics card is Intel HD5500. Running Windows 7.

[Calby]

Have you tried to replace the adapter?

[enstain]

No, since I do not have a spare one around. But it seems unlikely for it to break by lying on the table for 2 days. I'll look for one just in case, though.

[Calby]

Do you get any errors?

have you tried other hdmi cable?

have you run Lenovo test program from bios?

first off, can you see the external display in device manager?

if yes then it's a setting.

if no then try this,

try the display in other source (other computer or something that can provide picture over hdmi)

new hdmi cable

new adapter

If nothing helps, then it's mobo issue.

[enstain]

I do not get any errors. Windows doesn't react in any way if I plug in the monitor. The option does not come up in the "Screen resolution" menu or any other that I could think of. It works over VGA though.
Will try the bios test program, only tried the windows one.
As mentioned before, do not have another cable, but I will try this one on another computer, if I can find one.

[Calby]

Change the output on your display to hdmi it should fix the issue.

i did miss that it did work over vga.

[enstain]

If I switch the input, I just get no signal message on the monitor.
Ran the BIOS tests. Everything passed.
So I guess it's down to the adapter or the MB...

[Bob-II]

Simple test:

power everything off

connect the hdmi cable

power the monitor on first

wait 10-20 seconds

power up the T450

I've run into some hardware that need the external display on first. Why? Not sure. Strange video circuit design maybe?

B

[enstain]

The thing is that this setup was working fine for a while now. And I haven't changed anything. Just took my laptop home for the weekend (which I have also done before...).

[Calby]

Well something has happend, what I don't know.

It could also bee your display, you need to try some truble shooting to isolate the issue and rule out stuff.