Hello, my NES give a white screen when i turn it on. If i press reset it wirl boot the game no problem 100% of the time. I cut the pin 4 of the lockout chip. I think it may be unstable power when i turn it on and by the time i reset it it stable to boot. what you think?
The CIC is involved in the reset process I think. With it not operating in the correct mode because of the cut pin maybe it's function in that process isn't being done. The CPU could crash when things are powering up because the state is unstable and will remain so unless the reset signal is given. The CPU doesn't actually power up to a reset state. I do recall reading if you desoldered the CIC from the NES motherboard that you would have to press reset after powering on to get games running. That or hold the reset button down when powering on and releasing it afterward. I also read about some circuit you could add to keep the CPU in reset until power stabilized that you would add in where the CIC used to go on the motherboard. It might be similar to what is used in the Famicom or Top Loader which lack the CIC.
I tested with other cart and it work normaly just lunar pool that need the reset. The 2 nes do the same thing. thank you for your help
I have a Golf cartridge that I remember behaving the same way. I'm not sure what the reasoning is behind why it would require a reset. Maybe there's a bad cap on the game pcb.
