Apple IIgs to Commodore 1080 monitor hookup

Hi I have been trying to get a IIgs working with a Amiga/Commodore 1080. This should be a simple hookup...108x and derivatives support around 15.75khz scan rates and should work in analog RGB mode selection... It's not working. I see the composite sync squashed with a scope when hooked up to the monitor. Also the color signals are hit. Nothing on the screen. I see the video for a split second when switching from digital to rgb on the commdore monitor, its outta sync but you can see for a fraction of a second, so video signals are making it through... I tried also a 1084 and a 1902 with no success...I have checked the pinouts from several sources for both monitor and IIgs and they all match...RGB analog on the 198x series db9 connector...2,3,4...R,G,B and 7 composite sync...1&2 ground...simple enough no? I have tried long/short shielded and unshielded cables with no success. The IIgs RGB output is fine and works perfect with the original IIgs RGB monitor and cable... Anybody ever do this and have these problems...??? Or an idea? Thanks for reading Claude