Note that carts with a “Time Bomb” will no longer be able to launch .nds files when they detect that the system clock has passed a date determined by the flashcart firmware. One method to bypass this is to set the system clock to an earlier date.
The original R4 has no such thing. Most of the clones (but not all) do.
Edit: If you've had it for years without updating the kernel then it doesn't have a timebomb. The expiry date will be set 1 or 2 years after the release date of the kernel, and once passed, the cart requires a new kernel to work unless you set the date back (which causes other issues, mainly with SSL certificates as those have a set time period in which they are valid)
Simplest test is just to set your time far in the future (2030) and see if you get an error starting up. I wouldn't go on the "had it for x years without issues" because not all makers seem to be as consistent as updating it every n years.
Well, as long as you kept the kernel up to date (and they kept releasing updates) then you wouldn't run into the timebomb. It only becomes an issue if the team stops supporting the cart either because they want you to buy a newer cart or because they've disappeared.
Human vision is logarithmic, it's not linear. And nits doesn't tell the whole story of perceived brightness. OLED'S look brighter then LCD's even when both are set to the same nit values because of the higher contrast ratio on OLED's
"And nits doesn't tell the whole story of perceived brightness" it's not about perceived brightness it's about all HDR content in TV and movies being mastered for 1000 nits so it doesn't look right with anything lower, it's also about dynamic range
OLED's can get away with a lower peak brightness and still provide punchy HDR because of their contrast ratio. Like I said human vision is logarithmic. The higher the peak brightness the diminishing returns in perceived brightness.
@The Real Jdbye Oleds hit around 750 nits nowadays. The difference between a 1000 nit and a 750 nit isn't huge. It's only about a 4% increase in perceived brightness. Not huge at all. You'll need at least 2000 nit displays to notice a bigger difference.