My problem is a little unusual. I run a digital media company and have deployed an instore advertising system to Australia national electrical goods retailer. A simple view of the system is a PC outputting component video to a high definition bandwidth 8 way distribution amplifier. This then connects to more amplifiers through expansion ports to around 60 TV screens with component inputs. They are a mixture of LCD and Plasma screens from Sony, Samsung, Panasonic, Hitachi, JVC etc.
The PC is a local supplied unit with Intel Core 2 chip, ATI1650XT video card with 256Mb RAM using a component break out cable from the S-Video output. The PSU of the PC is 275 Watts and the card I found out should have 400 watts minimum. The card outputs at 720p at 60Hz. We show a loop of WMV and Flash files, some encoded to HD, but most aren't.
The problem is that in around 40 of the 100 stores I have deployed this to, some but not all screens in the TV wall suffer highly visible flickering on the screens. The system was installed by different installers around the country and not all stores suffer the problem although they all have the same PC. Recent testing in some stores had also found the following:
* If I connect a digital STB to the system instead of the PC and run it at 720p 60Hz, or 1080i there is no problem
* If I connect the PC directly to an affected screen, there is no problem
* If I swap cables on the screens, the problem follows the screen
* If I increase the PC output to 1080i the flicker improves but does not go away entirely. (Note, this card can only do 1080i at 30Hz)
Everything points to the PC, but when connected to one screen there is no problem. One last thing I noticed is that when I had my helpdesk VNC in to increase to 1080i while I watched in store, one screen I was looking at was flickering with the PC desktop on, but as soon as they opened up the ATI Catalyst Control Centre on the desktop, the flickering stopped.
When they closed it down it came back. This is just bizarre and I would welcome anybody's ideas or things to test further as my customers are at their wits end.