That's what we do at the shop to see if it's the jack not quite big enough to cause the switch.
If the display is new enough you consider taking it back to where you bought it.
We can also use a switch if all support fails to fix it.
My monitor is the ASUS VH236H. You can see it here..
I'm having a problem with getting audio using the headphone jack on this monitor with my headphones. The sound will continue to play through the monitors built-in speakers instead. No volume from headphones at all, even after turning the volume all the way up. I recently purchased this for use with a PS3 to use with HDMI and it works great but the sound is coming from the monitor..is there anything I can do? I called ASUS tech support and I was just told to try another set of headphones -.-