In our conference room we have laptop mounted on a lectern that displays on multiple TVs in the room. The laptop is connected via a VGA cable to a DM-TX-201-C, which in turn is connected via CAT5 to a media switch. This has been working fine for 18 months, but now all of a sudden the laptop will only project at 640x480 resolution. This occurred when our tech was reinstalling a High-Definition Digital Video Processor that had to go back to the factory for repairs. The laptop functioned fine while the DVPHD was out of the rack.
Here are the results of my troubleshooting:
•Laptop will work on high resolution until you plug in either a VGA or HDMI cable – then it will only run at 640 x 480. As we know, when you clone the display of a computer to a monitor with a lower resolution capacity then the laptop display will only run the resolutions supported by the attached monitor. The monitor in this case I’m assuming is the DM-TX-201-C Digital Media Transmitter installed in the lectern.
•The same thing happened when I disconnect both CAT5 cables going into the DM-TX-201-C. Even when there are no lights on the DM the resolution on the laptop will drop to 640x480 when a video cable is connected to the laptop. I tested this on two different laptops.
Input on the switcher shows up as 640x480.
My take on this is that for some reason the DM-TX-201 is only running at 640x480 or lower resolution. I have no why this happened since it was working fine earlier on this week.
Any thoughts on why this is happening? Any recommendations that I can pass to the technician.
