Samsung P2370 and ATI Moblity Graphics Card

I recently bought a Samsung P2370 LCD monitor in order to watch 1080p HD movies on my HP G42 laptop, which is using an ATI Mobility Radeon HD5470 graphics card. Much to my surprise, this combination did not work at all and was a total waste of time. Here is why.

The monitor screen size is 23-inch, supporting full HD resolution at 1920×1080 and has only one DVI input. Interestingly, the on-screen display shows that the monitor searches for signal on both analog (likely referring to VGA) and digital (DVI) inputs. This is perhaps because the same firmware code base is shared with another similar model, the Samsung P2370HD that supports VGA input, among many other things including a TV tuner.

I first tried to connect the monitor to a DVD player with DVI output and everything worked well, so I proceeded to connect it to my HP G42 laptop HDMI port via a cheap DVI-to-HDMI converter purchased from eBay. Although the PC booted normally, with the monitor showing BIOS POST messages and Windows logo, the display is not detected once Windows finished booting and the Screen Resolution settings in Windows 7 reported Another display not detected.

I tried to disconnect, reconnect, reboot Windows, reinstall driver to no avail. I also tried to install the Samsung driver for the LCD. The notebook graphics card has 3 outputs: LCD panel, VGA and HDMI. However, the monitor driver install utility only offers to install driver onto the LCD and VGA output, but not the HDMI output.

It then came to my attention that the P2370 was never detected – Windows played the “device connected” sound when I connected other monitors via HDMI, but not the P2370. The monitor worked well with other graphics cards, and the notebook graphics card HDMI output worked well with other monitors! So there must be something wrong with my special hardware combination. To my knowledge, unlike VGA where handshaking is optional and you can always force the graphics card to output to VGA port even when no monitor is connected, HDMI  has some compulsory handshaking involved and the monitor has to be detected before the graphics card can output anything.

I then tried MonInfo and surprisingly the P2370 could be detected properly, with all the parameters correct. I tried to create a custom monitor driver to use with PowerStrip, which did not help either because the graphics card did not ‘see’ the monitor! Not giving up yet, I tried Windows XP which does not have automatic monitor detection. This time round, the Samsung driver installation utility could install the driver to the HDMI output, but the HDMI port was still not visible in Display Properties. I then tried to launch Windows in Safe Mode where only the VGA driver is loaded, and the P2370 always displayed a clone of the laptop LCD, much like what happened during boot time. The Fn key combination to switch between clone/extended desktop did not work.

All this observations suggested that the hardware was fine and the problem was with the ATI driver for Windows which could not see the P2370 via HDMI for some reasons. My final attempt was to try various Linux variants, hoping that some Linux drivers may fix the problems. However, the same problem persisted:

1. On Linux builds where the graphics card was detected properly, no output on HDMI.
2. On Linux builds with no driver for the graphics card, the P2370 displayed a clone of the laptop LCD

This is a dead end. In the end, I decided to sell the Samsung P2370 LCD and get a Dell S2409W instead, which has served me well so far. During the troubleshooting, my research revealed that this is a common problem (it’s even in Google Autocomplete suggestion list, try to search for ‘samsung p2370 ati problem’) with no official answers from either Samsung or ATI, and no solutions available.

This problem may apply for other ATI card as well. The bottom line is not to buy Samsung P2370 and similar models if you’re using an ATI graphics card!