Need help repairing ThermoVision Scout ZX

[1nfinite]

Hi all,

I got a ThermoVision Scout ZX handheld from my grandpa. It's in pretty good condition overall and has been kept in the Flir case.

When I connect it to an external power supply, the green light lights up, but when I press the power on button, it won't turn on.

I can take it apart, but wondering if someone has any experience fixing these things?

Thanks,

~ Brandon