Printer firmware, what, why and for what reason? Let's start with when it is worth updating the printer with the latest software. After all, inside the printing device there is a brain, just like in a computer. And sometimes, when the device is working poorly, an update really helps it.

Where to get updates, of course on official websites. If there is none, you can try to find one for another country. Once I cured my MFP this way, downloaded it from the American market website, and it helped. But everything is at your own risk.

Sometimes printers and MFPs have unofficial firmware and even programs that help with various tricks. Before downloading and installing, carefully study this issue. Compare opinions on the Internet.

Sometimes there are glitches in the operation of a network printer under load from users connected to it, and as it turns out, you simply need to increase the RAM. Just add a bar similar to a laptop. 

If you are flashing the printer or MFP yourself, make sure that the power is not lost during the update. Most often, this procedure is done via a USB cable, its length and quality. Well, and read the instructions that the manufacturer packs in the archive with the firmware file or shows with an attention sign next to it!