About VGA Cable

SOURCE: 710s monitor wiring diagram to vga plug

DRIVER OF MONITOR LG 710S

SOURCE: I can't get a signal between my PowerMac G5 and my

Hello,
First we need to know your G5 and monitor are working, independently. Test these items first on known good computers and monitors. If they show working then;
If your G5 is per 1997 then it may be a true compatibility problem. If 1997 or later, then it could be one of several problems.
1. video card not working or not powerful enough or overheating
2. G5 power supply issues
3. video card may need to be re-seated
4. 3rd party RAM compatibility issues
5. try by resetting the PRAM
6. The monitor may have the brightness and contrast set to BLACK
7. The G5 DVI output may be off or failed. 
8. You can try this fix;
Go into System Preferences > Displays > Options (on the 2nd display) and selected "Disable Power Button". Problem solved, if inelegantly.
OR
change the other settings for displays.
9. Using the on-screen settings on the monitor, change to the lowest resolution, then if visible work your way up until it goes blank again.



See some supporting info here:
http://support.apple.com/kb/TA27012
and
http://support.apple.com/kb/HT2707
and

Here is you manual:
http://manuals.info.apple.com/en_US/PowerMacG5_UserGuide.pdf

Good luck

SOURCE: hello I just purchased a LG

The DVI cable must be faulty as the card does work with the VGA cable as you have stated.