If you're experiencing high impedance or a lack of signal in one or more electrodes, we recommend the following steps to identify and resolve the issue.
1. Basic Troubleshooting Steps
Check the electrode placement: Make sure the electrode is correctly positioned on the scalp and fully inserted into the cap.
Apply sufficient gel or saline: Ensure there is enough conductive medium (e.g., Signagel or saline) between the scalp and the electrode.
Confirm cap size and fit: The cap should fit snugly and cover all electrode positions properly.
Inspect CMS and DRL: These reference electrodes are essential. If placed on the ears, ensure gel is applied and contact is good.
Swap components: Try replacing the suspect electrode or cable with a known working one to isolate the issue.
Avoid gel bridging: Too much gel between electrodes may cause shorts and impact signal quality.
Ensure battery charge: Low battery may affect performance. Ensure the battery is charged above 20%.
2. Using the Testboard to Identify the Root Cause
Our testboard simulates an ideal electrical environment ("artificial head") and is a valuable tool to determine whether the issue is due to the device, cables, or setup.
Test A – Check the device
Connect the Neuroelectrics device to NIC as usual.
Use the flat black cable to connect all 8 channels + CMS and DRL to the testboard clips (for Enobio 8) or appropriate connectors (for Starstim 20/32).
Run a stimulation protocol in NIC.
If all channels show green impedance and stimulation runs correctly, the device is working properly.
If the protocol is aborted due to high impedance, the issue may be with the device itself. In this case, we will assist you with the next steps to resolve it.
Test B – Check the electrode cables
Connect CMS, DRL, and two electrode channels (e.g., Ch1 and Ch4) using the standard electrode cables to the testboard.
Create and run a bipolar stimulation protocol for these two channels in NIC.
If stimulation proceeds without error, the cable is likely fine.
If impedance remains high and stimulation is aborted, that specific cable may be faulty.
Repeat the test with all cable pairs (two at a time) until the faulty cable is identified.
For Starstim 20/32, CMS and DRL must always be connected to their specific clips on the testboard.
3. Additional Tips for Improving Impedance
There is a solution article with information about how to improve an impedance: