I tried to replace this magnetic buzzer by piezo but it does not work, it makes no sound, found explanation here https://www.murata.com/en-eu/support/faqs/sound/sounder/char/sch0007 - "You cannot produce a sound from a piezoelectric sounder by simply replacing an electromagnetic buzzer with a piezoelectric sounder in this circuit."
I also found another buzzer from similar cheap tracker tag and that one is 15ohm and is much louder. sadly it is also quite a bit bigger so won't fit inside. It looks like this one https://www.aliexpress.com/i/1005005047243506.html
Anyway the one on the board posted by parasquid is still not that bad, the other boards have the 10 ohm resistor replaced by higher values and those are more quiet. Also I don't see diode there.
As for the SPI flash pinout on the cheap NFCBoxLink ones I got last time - it really matches USON-8 package - VCC,GND,/WP,/HOLD pins are all in correct place and VCC, GND are connected. It is same SPI flash package as used on Raspberry Pico board - found 2MB chips here https://www.aliexpress.com/item/1005004379141351.html - will try to kill at least one NFCBoxLink board by adding it via reflowing by hot air. It is not that much useful there, I know, but still :-)
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I tried to replace this magnetic buzzer by piezo but it does not work, it makes no sound, found explanation here https://www.murata.com/en-eu/support/faqs/sound/sounder/char/sch0007 - "You cannot produce a sound from a piezoelectric sounder by simply replacing an electromagnetic buzzer with a piezoelectric sounder in this circuit."
I also found another buzzer from similar cheap tracker tag and that one is 15ohm and is much louder. sadly it is also quite a bit bigger so won't fit inside. It looks like this one https://www.aliexpress.com/i/1005005047243506.html
Anyway the one on the board posted by parasquid is still not that bad, the other boards have the 10 ohm resistor replaced by higher values and those are more quiet. Also I don't see diode there.
As for the SPI flash pinout on the cheap NFCBoxLink ones I got last time - it really matches USON-8 package - VCC,GND,/WP,/HOLD pins are all in correct place and VCC, GND are connected. It is same SPI flash package as used on Raspberry Pico board - found 2MB chips here https://www.aliexpress.com/item/1005004379141351.html - will try to kill at least one NFCBoxLink board by adding it via reflowing by hot air. It is not that much useful there, I know, but still :-)