Large screen only display part of the image, Signal need to scale, No display in the second half part of large screen – RGBLink VSP 729 User Manual
Page 94: Resolution is inadequate, Sending card can't take lower part, Large screen shaking, Sending card input recognition is not correct, Common questions and solution

7. Common Questions and Solution
VSP 729 User Manual 94
Large Screen only Display Part of the
Signal need to scale
Press 【SCALE】button in the processor and knob to adjust the actual
screen size of the screen, combined with button【POSITION】, including the
"width", "height" and "starting position", remember to touch the knob to
confirm.
No Display in the Second Half Part of
Resolution is inadequate
Please make sure the points of the screen width and heigh, choose the
resolution to be bigger than screen width by button【MENU】 under
OUTPUT RES, and touch knob to confirm.
Sending card can't take lower part
TS 802 can control the max horizontal resolution 2048, and vertical
resolution 640. Each CAT5 output is 320 pixels.
Sending card input recognition is not correct
It usually occurs in DBStar sendig card. U
se it‘s normal before, but screen