No Video from HDMI port on my Inspiron N7010

I'm trying to connect my Samsung TV with my Dell laptop through the HDMI port.

1. Another laptop does connect with my two Televisions (both are Samung) (i.e., video/audio signal go from the Laptop to the TVs).

2. My Inspiron N7010 used to connect successfully and then just stopped.

3. When I plug in the cable into the Dell HDMI port, the display settings do in fact show 2 monitors and the device manager shows "[TV]Samsung LED48" under the heading Digital Media Devices.

4. In display settings under the header "Multiple Displays" I have tried both "Duplicate These Displays" and "Show only on 2" without success.

5. Also when I plug in the cable in the laptop's HDMI port (and when I unplugged too), the laptop does in fact react - the laptop screen goes black for a second before reappearing and a connectivity tone is heard on the laptop.

6. The audio does go silent on the laptop.

7. Neither TV carries the Audio or the Video signal from the Dell Laptop.

In short, the Dell laptop does detect the connection but does not transmit audio/video signals to the TVs.

I have run diagnostics, tested for unwanted programs/viruses etc.  I have found nothing.  I have searched for updated video/monitors drivers without success.  Rollback drivers is not an option because the button is grayed out.  I have disabled/uninstalled drivers without success.  The device manager report that all devices are working properly.

Any ideas?