Laptop external monitor no longer being detected

Question

I have an HP ENVY TouchSmart 4-1215dx Ultrabook Laptop running Windows 8.1. All hardware is standard except I upgraded the 4GB of RAM to 8GB. Up until recently (2-3 days ago), I have had no issues connecting my laptop to external monitors via HDMI (no VGA).

Now, however, every time I connect anything to my HDMI port it simply does nothing. It doesn't detect or show the additional display when in Right-click Desktop > Screen Resolution. Also, when my monitor is just sitting without any input, it says No DVI-D Cable. The display will go into Power Save Mode in 5 minutes. When I plug in my laptop, the monitor immediately goes to sleep.

I don't know of an event that would have caused a change in functionality. The only thing that seemed to somewhat coincide with this is my OS recently (yesterday) got removed from the BCD and I had to rebuild the BCD from the system recovery command line tool in order to get it to boot.

I have tried rebooting, reconnecting the monitor, and plugging in the monitor before I start up my laptop. I also tried re-installing the Video Driver using the HP-provided drivers here

Any ideas where else to look or what else to do? I have looked around and haven't been able to find any leads. My only thought is that it's a hardware problem and I somehow messed up my HDMI port. Thoughts?

Solution

Standard battery of tests to isolate the issue, in order:

1) Use a known good HDMI cable to connect the monitor to your laptop. If it works, your cable is the problem.

2) Use a known good HDMI cable to connect the monitor to another device. If it works, your laptop is the problem.

3) Use a known good HDMI cable to connect another known good monitor to your laptop. If it work, your monitor is the issue.

1 Is easy and cheap. 3 is easy and expensive (try connecting via another port on the monitor, DVI or something - might be the HDMI port on the monitor). 2 is the hard one - could be the HDMI port (try other ports) or could be the software.

I suspect it's the laptop. Try installing the manufacturer's drivers rather than the ones from HP, if that's possible.

Comments

[Ramhound]

Its possible you had hardware fail on you, but if that happen, its unlikely you did anything to make it fail.

[Mike DeMille]

Well it's definitely my laptop then. The monitor's I've plugged in for sure work, and the HDMI cables are good because they work in other computers. I wish I had a VGA port, but I don't. Maybe I'll have to break down and buy a VGA to HDMI converter. Even if it is super expensive. Where would I be able to find the manufacturer's drivers? Or, for that matter, even the manufacturer of my laptop? I thought it was HP... On that note, however, I was probably going to reimage my laptop after this semester is over. I wonder if that would fix it?

[ChimneyImp]

You'd want the drivers for the manufacturer of the video card, not the laptop as a whole. Check Device Manager if this is Windows for the name and manufacturer of the video card and go from there - maybe you're lucky and it's software, not hardware.