Fitting/HIT Unit Not Connecting or Functioning Correctly

Product(s): Primus · Measure · Unity
Applies to version: All current versions
Audience: External – Customers
Difficulty: Advanced
Estimated resolution time: 20–40 minutes
Last updated: 2026-06-27
Article type: Troubleshooting guide

Quick summary

The Fitting or HIT unit is not connecting to the PC or software, or is not functioning as expected. This guide walks you through system requirements, cable checks, software detection, and audio settings to restore correct operation.

⚙️ Before you begin

Make sure you have administrator access to the PC.
Have a spare USB cable and power supply available for testing.
Close the Fitting software before starting.

Step 1: Verify system requirements

Does your PC meet the minimum system requirements for the Fitting/HIT unit?

✅ Yes → Proceed to Step 2.
❌ No → Upgrade your system to meet the minimum specifications. Contact Auditdata Support if you are unsure of the requirements for your specific unit.

Step 2: Install all Windows updates

Are all Windows updates installed and current?

✅ Yes → Proceed to Step 3.
❌ No → Go to Settings → Windows Update and install all pending updates. Restart when prompted.

→ Check if the issue is resolved. If yes - you're done ✓. If no - continue to Step 3.

Step 3: Perform a full power and USB reset

Have you unplugged all USB cables and the power supply, restarted the PC, then reconnected?

✅ Yes → Proceed to Step 4.
❌ No → Take these steps:

Unplug all USB cables and the power supply from the unit.
Shut down and restart the PC.
Once the PC has fully restarted, reconnect the power supply first, then the USB cable.

→ Check if the issue is resolved. If yes - you're done ✓. If no - continue to Step 4.

Step 4: Confirm unit connections

Are the USB cable and power supply securely connected to both the unit and the PC?

✅ Yes → Proceed to Step 5.
❌ No → Reconnect the USB cable and power supply, making sure each connector is fully inserted.

→ Check if the issue is resolved. If yes - you're done ✓. If no - continue to Step 5.

Step 5: Verify accessory connections

Are all accessories (transducers, probes, cables) correctly connected to the unit?

✅ Yes → Proceed to Step 6.
❌ No → Reconnect all accessories securely. Refer to the unit's setup guide if unsure of the correct port for each accessory.

→ Check if the issue is resolved. If yes - you're done ✓. If no - continue to Step 6.

Step 6: Confirm software detection

Does the Fitting software display the device as "Connected"?

✅ Yes → Proceed to Step 7.
❌ No → Close and relaunch the software. Verify all physical connections are secure. If still not detected, restart the PC and relaunch.

→ Check if the issue is resolved. If yes - you're done ✓. If no - continue to Step 7.

Step 7: Check the power LED

Is the unit's power LED on and steady?

✅ Yes → Proceed to Step 8.
❌ No → Check that the power supply is properly connected. Try a different power outlet. If the LED still does not light, the power supply or unit may be faulty - proceed to the escalation path.

Step 8: Check sound output settings in Windows

Is Primus/Measure/Unity set as the default audio output device in Windows?

✅ Yes → Proceed to Step 9.
❌ No → Go to Control Panel → Sound and set the correct device as the default output.

→ Check if the issue is resolved. If yes - you're done ✓. If no - continue to Step 9.

Step 9: Disable sound enhancements

Are sound enhancements disabled for the Primus/Measure/Unity device?

✅ Yes → Proceed to Step 10.
❌ No → Go to Control Panel → Sound, right-click the device → Properties → Enhancements → check Disable all enhancements → OK.

→ Check if the issue is resolved. If yes - you're done ✓. If no - continue to Step 10.

Step 10: Connect the unit directly to the PC

Is the unit connected directly to a USB port on the PC (no hubs, extensions, or sound booth cables)?

✅ Yes → Proceed to the escalation path below.
❌ No → Remove all USB hubs, extension cables, and sound booth cables. Connect the unit directly to a USB port on the PC.

→ Check if the issue is resolved. If yes - you're done ✓. If no - proceed to the escalation path below.

🔺 Escalation path

If none of the above steps resolved the issue, contact Auditdata Support.

Please have ready:

Product name and version number
Device model and serial number
Firmware version
Your account name and contact details
Which steps above you already tried
Exact error messages or codes shown
Whether the power LED is on or off
Screenshots if available

✅ Expected outcome

After completing these steps, the Fitting or HIT unit should be detected as "Connected" in the software, the power LED should be steady, and sound output should function correctly.

📝 Additional notes

USB hubs and extension cables are a common cause of intermittent connection issues - always test with a direct connection first before replacing hardware.
If the unit was recently updated or reinstalled, make sure Windows Updates are fully current before troubleshooting further.
Related articles: Fitting Unit Board Not Detected · No Power or Board Not Detected · Transducer Not Detected or Misidentified

Need more help? Visit the Auditdata Help Centre or contact our support team.