I'm sorry to hear that you are having some difficulties with your Samsung BX2450.
Please try to connect your notebook to another HDMI device (a TV maybe) to see if the HDMI Audio is actually outputting audio at all. Based on the post, I cannot verify that the issue is not with your notebook. There may be another Audio Output setting somewhere in your software that turns the HDMI Audio on or off, but that would be a question for the notebook manufacturer. Again, I'd try to connect the notebook to another HDMI first. Keep me posted on what happens and I'll try to help you out further.
I have a Samsung BX2450 monitor (24") with two HDMI jacks. I ordered a cheap HDMI cable from Amazon (link), and I tried to use it to connect my Gateway NV53 laptop to the monitor. This laptop has an integrated AMD chipset which should support HDMI output, which includes both video and audio. Video output on the monitor works fine, but when I plug my headset into the monitor's audio out jack, no sound comes through.
(Why don't I simply plug the headset directly into the laptop, you might ask? I was testing my new HDMI cable in anticipation of the arrival of a device I ordered which converts analog RCA signals [the old red, white, and yellow plugs] to HDMI signals. I want to plug my old last-gen game consoles into the monitor. Therefore, I need to have the HDMI audio working if I ever want to hear the audio output of the device.)
-I first went into the Control Panel and viewed the laptop's audio devices. I saw an "AMD HDMI output" which is both set as the default device and reported by Windows as working. (This was the most commonly parroted solution in the forum threads I searched, but it doesn't solve my problem.)
-I plugged the HDMI cable into the monitor's other HDMI jack, which had no effect.
-I updated my Catalyst drivers. Windows' Device Manager confirms that the HDMI audio driver is up to date. It made no difference.
-I unplugged the monitor's power for a few minutes as advised elsewhere. The problem persists.
This forum is my last resort before my most likely solution of purchasing a cheap RCA to 3.5 mm audio adapter. Please reply.