Bosch EX36N Installation Instructions Manual page 26

Horizontal
Scan Lines,
Rolling Up
or Down.
Reversed
video or
faded image
Ground
Looping on
video cable
Low voltage
20
Check the coax
cable shield is not
touching ground, e.g.
at couplings.
Check voltage at
input power cable.
Must be >10.5V dc
or >12Vac for
camera section.
Check video leads
for reversed
connections.