I read the article and was having a hard time fully understanding which components in a system are actually being damaged by the higher 5V. I can understand the wear on the cart (since it's taking more voltage than originally specified), but can someone explain this better?
https://db-electronics.ca/2017/07/05/the-dangers-of-3-3v-flash-in-retro-consoles/#What_Damage_Can_Be_Caused
Prolonged use of components outside of their specified tolerances inevitably leads to failure. On the console side, the stress is excessive current output on digital outputs when driving a logic high. On the cartridge side, the stress is excessive heat dissipation due to conduction of the clamping diodes. I have already heard from several friends that their NES consoles have died most likely due to their admittedly heavy use of cheap multicarts. These are particularly bad. I would avoid these like the plague. I suspect poorly designed Everdrives will require more time before we start seeing failures.
What does this mean? Does it impact the voltage regulators which convert the power source in to 5V normally? Or something else on a given board?
Basically, electronic circuits are designed with a balance. If you have 5V pushing a motor you're expecting the motor to consume a certain about of current if you put a 3V motor in its place it...may spin faster, for a while, but even if it doesn't fall apart from going too fast it will eventually fail from excessive current that it can't use.
With data, I admit I'm not as experienced as I am with more conventional electrical loads. However the concept is the same. You now have less impedance than a normal cart. Therefore the 5V is going to push more current through the flash than the flash is rated for. But it will not only put more through the flash than it expects but you are flowing more current THROUGH THE ENTIRE CIRCUIT (as always, current flow through a circuit is the same everywhere), most of which Sega made, which means your poor Genesis is now being asked to supply more amps than it was supposed to but it's also experiencing that over-current through...well, exactly what I'm not sure, and it depends on the system, but I think its possible you could lose RAM, CPU, or anything else that lives on the cart bus.
This news isn't going to stop me from using flash carts but it does make me kinda not want to buy any more until they start designing entire projects instead of just wiring flash directly to your cart slot. This has less to do with reliability and more to do with just not wanting to support hacks.