Swapping boot and ROM chips on N64 cartridges

Is this as simple as it seems? Find a matching game that uses same boot chip and swap it over to a seemingly dead board? Or do the opposite and move the game ROM chip over to a board with a working boot chip?

Is there a way to test the pins of the current installed chip to verify if it is bad or not?

I believe that the boot chip I have is CIC-NUS-6102. It's for killer instinct gold. I've gotten three bad ones in a row now and i'm going to fix at least one of them. Can't have a flaky game in the collection :)

I figured someone here may have done this before.

Sorry it's an old post, but I'm sure other folks are curious.

The main symptom of CIC failure is the console resets during play or stays on a black screen at boot. Even if this is true, usually it's a smaller problem of cleaning all of the PCB contacts. (Too many products and techniques to go into and doesn't address the OP's other questions.)

A Logic Analyzer is the best tool to determine if the CIC is working. N64 Game PCB Image The linked image shows a nice clean trace coming from pin 43 (next to the 44) that goes to the far side of the CIC chip. It's hard to say exactly which CIC pin but there aren't many CIC pins actually used. Pretty much any kind of a digital signal on this pin would suggest it's working. Probably good to compare the same signal on a known working game, for example if there is a group of 64 Hi/Lo changes on the good cart and only 32 Hi/Lo changes on the bad cart it could still be a CIC issue.

For reference the CIC is actually a Sharp SM5 4-bit Microcontroller that was customized for Nintendo.

All of the CIC 6102 chips should be interchangeable. There are some CIC 6102A that should work but I wouldn't promise it.

Also since this was first posted, an Ultra CIC has been created that can be used to replace a CIC, this may affect the collecting aspects of a cartridge, but could be a good solution for a player.