How Can I power the Jetson TX2 develop kit up with the converter of HDMI to VGA or with out a monitor?

Can I power the jetson tx2 develop kit up with the converter of HDMI to VGA? If not, Can I power it up without a monitor? More thanks.

Jetsons work fine without a monitor. The trick is that if you want to use the GPU for CUDA, then you would need to install a virtual X server. Here are some semi-random URLs related to this:
http://ubuntuhandbook.org/index.php/2016/07/remote-access-ubuntu-16-04/
https://devtalk.nvidia.com/default/topic/1001017/jetson-tx2/remote-desktoping-into-jetson-tx2-from-windows-10/post/5123184/#5123184
https://devtalk.nvidia.com/default/topic/995621/jetson-tx1/jetson-tx1-desktop-sharing-resolution-problem-without-real-monitor/post/5159559/#5159559

NOTE: VNC and desktop sharing use a virtual desktop.

VGA lacks a wire which is used for the video driver to query the monitor for its setup information. Automatic configuration is not possible with a VGA-to-HDMI adapter. The DDC wire passes what is known as EDID data, and this is equivalent to what the old VGA days called an install disk for the monitor (monitors didn’t really have drivers in the usual sense, but they still needed timing details configured…these are the details of valid timings).

More thanks. Can I boot it without a monitor?

Boot does not require a monitor. Setting up the context the GPU uses requires either a monitor or virtual equivalent. You will have no trouble logging in over ssh or serial console without a monitor.

Interestingly enough, the major cause of people thinking their Jetson failed, when it is really working, is video setup failing. Lack of video in no way implies boot failure. Video is a very poor way to determine if the system failed.