car's pc with iva d300 monitor

i have IVA-D300 installed. now, i want to built CAR's PC with IVA D-300 become a monitor for that PC. output from PC for video is VGA. and my IVA-D300 brain have composite input abnd navigation input ( RGB ). if i use composite input, the text can't be readed (Blurrr . and i already read at mp3car, there is a way to connect VGA output to IVA-d300 . navigation input at IVA-D300 can uses for that. but actually nav input receive RGB signal with only csync. otherwise....output VGA have RGB and Hsyc and Vsync. that not a big problem. with combine V and H sync, we can have C sync signal. and i have download the schematic from that forum. the schematic use 74LS86(XOR) to combine 2 signal to provide csync. but i have make twice, and at my monitor don't display anything. it's like we not plug any input at nav input. is that any mistake for that shematic? or mybe my iva-d300 brain have a problem? or anymore trick to activated nav input for that shematic? because i already activated nav input at the software iva-300 ( nav : ON ) thank youhow to biuld car's PC with IVA-D300

yes, it is. currently the project that i was do same as with the goods that you give me at http://www.cablestogo.com/product.asp?cat%5fid=3010&sku=27388. sorry if my english too bad. just for help, please open this thread http://www.mp3car.com/vbulletin/lcd-display/111828-people-trying-connect-their-pcs-alpine-rgb-input.html i was do like that, but it's never work! so who can help me???how to biuld car's PC with IVA-D300

hellppp please....how to biuld car's PC with IVA-D300