J202 & J404 Battery Polarity Issue

The most common issue experienced with J&J devices is a battery polarity problem. There is a capacitor in the device that can become overloaded if batteries are left in the amplifier for an extended period of time, which can cause the amplifier to not be recognized by EEGer. To troubleshoot this, follow the steps below:

1. Unplug the amplifier and open its battery compartment.
2. Remove the batteries from the amplifier - ensure that there is no leakage from the batteries or signs of corosion within the battery compartment.
3. Leave the batteries out of the amplifier for at least 24 hours. This will allow energy in the capacitor to discharge any residual energy.
4. After 24 hours, put fresh batteries back into the amplifier. Ensure that the batteries are oriented correctly within the amplifier, as misalligned batteries can cause serious damage to the device.
5. Reconnect the amplifier to the computer and attempt to run a session. Observe if there are issues or if the amplifier is recongized and reporting accurate signal/impedance readings.