If the grey scale is right you you should not see any
retrace lines . If you turn down the brite, contrast &
color level you should get a black or near black screen.
Dont forget to turn off any auto color buttons to test.
If its an older XL with the upright steel chassis & modules
it may have a "kine bias" control or switch, try that.
Been too long to remember.
Newer XL's with one small chassis can have different problems.
73 Zeno
