Boss PSA-120s adaptor help

[fretzburner]

Hi,my PSA-120s adaptor is not working well and cannot handle my RC50 but ok with CE3.I opened it and see a burnt resistor.Anybody here with this adaptor to share the resistor value.it is R2 in the picture at the lower left corner of the pcb.

image
I hope somebody here is kind enough to open their adaptor to check the value.
Thanks

[Processaurus]

Looks like the part is marked ZD1.  Zener diode?