Doesn’t sound like it’s the charger if you bought a replacement and it doesn’t work.
I bought one of these for my f7 (didn’t like the original charger as I had to use the pin adapter):
Powseed 36W AC Multi Voltage 5V 6V 7.5V 9V 12V 13.5V 15V Power Adapter Supply Switching DC Tips Selectable Freely for Household Electronics LED Light Wireless Router DVD CCTV Power Bank BT Speaker https://www.amazon.co.uk/dp/B06XK9TXBB/ref=cm_sw_r_cp_taa_9f0ACbH5RHJR0
Means I can use it with other devices if needs be as well.
Cheers