XO Self Test/Display

The display test of the XO laptop goes through several steps. Each step pauses for a short time while the display is switched between frozen and live several times, as a test of the display controller and display memory.

step	screenshot	note	method
1		Horizontal colour bars. You should check that the colours are all present, and look normal and clear.	.horizontal-bars16
2		Vertical colour bars. You should check that the colours are all present, and look normal and clear.	.vertical-bars16
3		A diagonal gradient between green and red colours. The most likely to show display noise as a result of EMI components on an XO-4.	gvsr
4		A diagonal gradient between green and blue.	gvsb
5		A horizontal gradient; black on left, white on right. Look for non-linearities.	hgradient
6		A vertical gradient; black on top, white on bottom.	vgradient
7		A crosshatch, white lines on black background. Look for lines that are not straight. The test also dims the backlight in steps at this point.	crosshatch
8		A series of filled rectangles are drawn in random positions with random colours.	random-selftest

The method column above can be used to lock a test on screen; for example to show the gvsr test image;

ok select /display  gvsr  key page unselect

Press a key and the test will end.