I've made good progress but I could use some help. The above is Lost World - Jurassic Park for the Genesis running via RGB from a Mega Drive 2 in 60hz mode. So far I've forced +5v through a 10kohm resistor into the Fast Blank Input pin on this TV to force the screen to be nice and black until RGB is fed into the OSD RGB input pins. What we get is the above after 75ohm resistors have been fitted. There is 0 difference that I can see with or without the sole resistor on all three lines. Red is visible, green is visible and blue is visible but the images are all washed out or overdriven, I can't decide which. Sync is handled by plugging in the composite video cable into the composite input jack with the TV set to the appropriate A/V input. This: http://133fsb.wordpress.com/2010/05/22/adding-an-rgb-input-to-a-cheap-generic-ntsc-tv/ Has been essentially identical to what I've done so far, though upon removing what I thought was resistors it seems they were capacitors as they popped from the heat, oh well. What I can't quite decide is if this is related to the console outputting PAL or if the video encoder for this TV (DCT814B, good luck finding a datasheet I found a pinout within a Daewoo service manual) just sucks for being forcefed RGB. The picture overall looks correct as the above shows just with messed up colors.
Cool this remind one of the first mod have done a long time ago on my cheap Deawoo TV to display a VS. system PCB. RGB is RGB, no video color encoding used (no PAL or NTSC) if the output is at 60Hz it should be fine. I'm pretty sure this is only going to work with TV that while you are in the OSD menu you don't see the picture at all. If the menu just an overlay mixed over the currently show picture I don't think it's going to work.
That's what I thought about RGB but I wanted to be 100% sure (encoding that is). The picture above was taken without engaging the OSD menu but I'll try again later. For all I know the RGB inputs may not be as listed in the service manual but arranged differently causing the funky colors. OTOH I may just need to match the impedance input properly but seeing as the SMD components are long gone I may just have to go through trial and error. But hey it worked!
Sorry for the bump, but is it entirely possible that your connections tapping into the IC are wrong? My TV had the same as 133mhz. All Sanyo based IC's. Sanyo LC863332/28/24/20/16A (OSD / Fast Blanking IC, etc) Sanyo LA76810A (Jungle IC) *EDIT* I got mine to work ok. Your connections on the IC must be wrong I reckon... http://www.assemblergames.com/forums/showthread.php?t=37393