Spotlight Cam Plus suddenly offline and never wake up again

I have 4 Spotlight Cam Plus up and running for months without issue. Yesterday monring, one of the camera went offline and has been never work online again. Both batteries in the cartridge were around 70 to 90% before it's offline. I took out the battery and recharged both batteries to full and put them back again but it's still offline. Light was not blinking when i pushed the button on the top of the camera. Is there any hidden reset button or trouble-shotting tricks that i can further drill into the root problem, please?