Radio Burn to 12V - DIODE?

[acuarianojm]

I try to add a LiPo battery to the radio to give greater autonomy, but I was wrong and put a 12V battery and the radio was burned.

I disassemble the radio and remove the fuse that was burned and the diode, but the diode I broke to disarm.

I need to know what is the code of the diode to be replaced.

I think it's a zener diode 6.3 V. Is this correct?

Thank you very much!

All the best
Juan Manuel