Hey there! I totally get the stress of dealing with a production line shutdown in the middle of the night. That 'A.17 Resolver Error' on an older servo drive can definitely feel cryptic, but don't panic! Here's a systematic approach you can try before calling for expensive emergency support:

1. **Safety First**: Lock out/tag out the equipment and verify power is off before touching anything.

2. **Check the Basics**: Verify your power supply is stable and within specifications. An A.17 error specifically indicates a resolver feedback fault, so focus on the resolver system.

3. **Inspect Cables**: Check the resolver cable for physical damage, loose connections, or compromised shielding. These older cables can degrade over time.

4. **Resolver Connections**: Verify all resolver connections at both the motor and drive ends. Clean any corrosion and ensure tight connections.

5. **Motor Check**: If possible, temporarily swap the servo motor with a known good one to isolate whether it's a motor or drive issue.

6. **Drive Parameters**: Check if any drive parameters have been changed recently. Sometimes a simple parameter reset can resolve the issue.

7. **Environmental Factors**: Look for signs of moisture, vibration, or temperature issues that could affect the resolver system.

8. **Document Everything**: Keep notes of what you've tried - this will help if you do need to call for support later.

Since it's a 10-year-old system, component aging is a real possibility. If the resolver itself is failing, you might need replacement parts, but at least you'll have a clear diagnosis before making that emergency call. Good luck, and I hope you get that line back up quickly!