Nintendo Entertainment System screen question

[jackhandy566]

I got three nes's. now i had to replace one of the cart pins on it. but with all three they have a different color if say the game doesn't start up right away or just before it does.

one shows white on the screen
one shows blue on the screen
one shows red on the screen

what does this mean? a different video card on the motherboard? a different motherboard brand? just wondering. thanks.

they are all the 1st generation model shell. side loader w/ the flap on the left in the front. NTSC-U/C region.

[133MHz]

The color of the screen when no cart is inserted doesn't really mean anything. Different colors appear because when there's no cartridge, the data bus pins are left floating and thus are very prone to interference. Any piece of electromagnetic garbage floating around the airwaves could be interpreted by the video system as valid data, producing a solid color screen.

Minute hardware differences like logic chips from different manufacturers and passive component tolerances can introduce all sorts of variables that won't affect normal operation whatsoever (since the system is designed with those tolerances in mind) but can provide ground for all sorts of interestingly weird behavior when the system is in an undefined state.

[jackhandy566]

cool stuff. yeah it's just a slight second before the cart starts up. if i hold down the power button for say 10 seconds. otherwise i missing it pressed the power button quickly. it wasn't the pin connectors. i knew one of them was going so i got a new 72 pin n replaced it yesterday n still shows up so i figured it was something on the motherboard or video chip.

[NintendoNerds]

...one of them was going so i got a new 72 pin n replaced it yesterday n still shows up so i figured it was something on the motherboard or video chip.

Interesting that it's still not working. Does this happen with every game cart you try and does each cart produce the same exact results on the same system?