PTH-9C (CO2 meter) is defective, how can I repair it?


I purchased the Inkbird PTH-9C (CO2 meter). It worked well for a while while it was at home. About two weeks ago, I went on vacation and disconnected the device from the USB charger, but I didn’t turn it off. During my absence, the device’s battery completely discharged. When I returned, I plugged the device back into the charger and fully charged it. When I tried to turn on the PTH-9C, it seemed to keep restarting, even though the screen lit up on the first attempt. Nevertheless, I attempted to calibrate it. During calibration, the screen’s brightness kept fluctuating between light and dark. This behavior continued after calibration. Upon attempting to turn it on and off again, the buzzer started beeping constantly, similar to the annoying hum of a large mosquito. The device did not respond to button presses, and the screen displayed nothing. After pressing the power button multiple times, I finally managed to turn off the device.

Could someone please provide an advice on what might be causing this and what steps I can take to ensure that my PTH-9C functions normally again?

If you need additional information, I am available. I can provide recordings of the device’s behavior, especially the continuous beeping. Furthermore, I have already measured the voltage on the battery, resulting in a reading of 3.5 volts, whereas the specified voltage for this battery is 3.7 volts. I have also attempted using another battery that precisely matches the specifications, but the device’s behavior remains unchanged (keep beeping constantly, no response to button presses).

While I don’t even have the schematic for the device, discarding it simply because a single component may be faulty seems too wasteful and impractical to me!

Best regards,

This product has a 1-year warranty.
Could you provide a video of the problem to email