Knowledge Base

Problem

The Noldus USB I/O box's power LED is off (or only blinks occasionally) even though the USB LED is on and the device appears connected. No power or TTL signal output is detected from the device.

Details

When the USB I/O box's USB LED is on but the power LED is off, this indicates an internal hardware fault — the device is recognized by the PC over USB but the internal power regulation or output circuitry has failed. This is distinct from a driver or software issue. A TTL-port tester can confirm absence of output power. The device must be replaced; it cannot be repaired in the field. Replacement is covered under an active NoldusCare service contract.

Solution

1. Confirm the fault by connecting a TTL-port tester to the I/O box output ports — if no power is detected and the power LED is off while the USB LED is on, the device has an internal hardware failure.
2. Verify that the USB cable is securely connected and try a different USB port or cable to rule out a connection issue.
3. If the fault is confirmed, contact Noldus Support and provide your NoldusCare contract details and the device serial number.
4. Noldus will arrange replacement of the faulty I/O box under the active NoldusCare agreement.
5. Once the replacement arrives, connect it to the PC, allow Windows to install the driver, and verify the power LED is on before resuming experiments.