No red output

[RedXT]

I have a acer z5101 all in one computer and everything is fine with the built in display but when I connect a second monitor to the vga out the red displays as black.
The second monitor and cable works ok on another computer so I am thinking its a hardware fault either in the vga output or something

any ideas would be appreciated

[lsemmens]

You've answered you own question. Is there an HDMI output you could use?

[RedXT]

yea but acer site say no video out on hdmi for my model.