U2711, cannot unlock, #10

I've read the various forums on this (extremely troublesome) issue, and none of solutions are working for me.

The 3 year warranty expired on November 26, 2015. I used this monitor with an old laptop with a VGA input. I recently tried to start using it with my new laptop (which has HDMI, but not VGA). The monitor is locked, and will not allow me to do anything. I've repeatedly tried multiple combinations of the stated solutions provided in this forum (holding in Button 5, simultaneously holding in Buttons 4 and 5, powering the monitor on with various cables inserted in various configurations while powering up the computer, etc), and nothing works. I have no computer that will allow me to plug in a VGA cable, so I can't revert to using the VGA to reset the video input.

In particular, holding in Button 5 just shows the locked symbol for 4-5 seconds, after which the monitor returns to bouncing around a graphic saying "No VGA Cable". Holding in for 15 seconds or a minute and 15 seconds makes no difference.

Is there any way to hard-force a factory reset on this monitor? I'm frustrated and getting quite angry with this ridiculous interface.