How to reset the display resolution, ECO HD

[ttdwwx]

Amcrest ECO HD, 8 channel DVR

So.. I set the display res to 1920x1080 and my monitor doesn't support it - no problem I figure, I'll just set it back to a lower res. The screen flashed for a long time (probably trying to sync up or something) and now it's black. Now I've tried plugging the DVR video output (both HDMI and VGA) into various monitors (even HD 1920 monitors) and I get nothing but black, turning the DVR off and on. How do I reset the display back to the lowest, or fix the issue of nothing but black even on a HD monitor? Perhaps holding some buttons while hitting the power button? Thanks.

Follow up: I was able to access the display resolution thru the web interface however after setting the res lower, I'm now getting...
--upon bootup: flashing
--then after booted: sometimes a black screen/no signal -and- sometimes a scrambled signal with monitor stating a res of 4096x806 (this is only 1600x1200 monitor)

[Melvin]

Hello ttdwwx,

Please try setting the resolution to 1280 x 1024 and try with a VGA monitor. Ensure that only either VGA or HDMI is connected at a time.