Rooted PiPo M7 Pro and was running beautifully.

With “Root Explorer” I attempted to make a small change in LCD density following this link:
http://forums.androidcentral.com/virgin-mobile-optimus-slider/135152-mod-root-how-change-system-lcd-density.html.

(extract)
2) Open root explorer and when prompted for super user access, click always allow.
3) Scroll down to /system and click it
4) If you are running a custom ROM, /system may already be mounted as r/w. You can tell by looking in the upper right hand corner of the screen.
If the button says "r/o" you are already mounted and can move to the next step
If the button says "r/w" tap it once to mount the system as r/w. It should change to "r/o"
5) long pres on the file build.prop. When the menu pops up, scroll down and select open in text editor.
6) Scroll down to the bottom of the file and add the following line
ro.sf.lcd_density=147
IMPORTANT Make sure there is at least 1 blank line under the new line you just inserted.
7) After editing the line, press the menu button on the bottom of your phone and hit save and exit
8) Reboot your phone which will build a new property file with your edit in it.
To return to stock density you can simply delete the line and reboot.
Thanks:
KSmithInNY for the assist.

Followed the above but would not reboot. Would not recover. Would not go back to factory default.
Only activity I can get on screen for a few seconds is the green battery after which the PiPo logo appears and seems active but progresses no further. Appears to be in some kind of a loop.
I read somewhere that the RK3188 Rockchip was unbrickable.  Help Please!