HDMI causes black screen

[ukbb]

If I connect my desktop PC to my office TV via an HDMI cable both screens are black and I have to reboot the PC to clear it. I tried hooking my laptop via the same cable and TV and it works fine. Any ideas on how to get it working with the PC? The PC is running Windows 7 SP1.

[admin]

The booting sequence may be important, so turn on the TV first (switch to the right input) and then turn on the computer. If this doesn't work, it may be a driver issue and you should look for updated video drivers for your PC.

[ukbb]

The booting sequence may be important, so turn on the TV first (switch to the right input) and then turn on the computer.

Only problem here is that I can only select an input on the TV that is actively receiving a signal. Otherwise it is greyed out. I'll try the drivers and see where that goes.