Date: 202007
Local time of day: 0601-1200
Location: ZZZ.Airport, US
Aircraft: B767-300 and 300 ER
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Cargo / Freight / Delivery
Flight phase: Cruise
Airspace: Class A ZZZ
ATC / advisory: Center ZZZ
Aircraft component: Compass (HSI/ETC)
Component problem: Failed
Reporter organization: Air Carrier
Reporter function: Relief Pilot; First Officer
Reporter qualification: Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Second reporter function: Captain
Anomaly: Aircraft Equipment Problem Less Severe; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance; Flight Crew Returned To Departure Airport; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Landed in Emergency Condition; Flight Crew Landed As Precaution; Flight Crew Diverted
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: We had an uneventful preflight; just a little late for MX (Maintenance); normal Taxi and Takeoff. In the final climb and level off at FL 370 the CA (Captain's) HSI failed and we smelled electrical fumes. The HSI flickered for a little bit and went out with a bright flash in the screen. The CA turned over the plane to the FO (First Officer); and the CA and I were running the appropriate QRH (Quick Reference Handbook) checklist for HSI failure and Smoke; Fumes and Fire. I contacted Dispatch and he acknowledged and he ask if we want to continue to ZZZ1. With the lack of EVAS (Evacuations) and one HIS; we didn't feel comfortable to continue and Dispatch ordered us to go back to ZZZ. After we explained to ATC our situation and intention to divert; ATC [gave us priority handling] and we landed with no further complications.


Second narrative: Shortly after top of climb of FL370; CA (Captain's) HSI and ADI brightness surged to full brightness with no input from the pilot. Pilot Monitoring heard a clicking sound. Entire crew smelt fumes similar to an electric burn smell. Soon the CA HSI had a bright red square in the middle of it. CA HSI went bright orange with the appearance of an extremely bright-looking dot in the center of the HSI. The dot looked like a spark in appearance. CA HSI fails. CA EFI switch pressed. HSI comes back with the same bright orange appearance. CA HSI fails again soon after. CA then transfers controls to PM (Pilot Monitoring). ADI turned blurry at this time. Both ACARS AOC (Airline Operations Communications) function fails shortly after. We ran the QRH for 'Smoke; Fire or Fumes'. The source of fumes appeared obvious. When we saw HSI fail; the smell dissipated. While PF (Pilot Flying) and PM ran QRH; the relief FO (First Officer) called Dispatch and MX (Maintenance) on SATCOM. MX and dispatch recommended returning to ZZZ. The entire crew did not feel comfortable continuing to ZZZ1 but did feel comfortable returning to ZZZ. We advised Center of the situation and that we intended to return to ZZZ. Center [gave us priority handling]. We advised them of SOB (Souls on Board); FOB (Fuel on Board). Fire trucks were waiting for us at ZZZ. They inspected the aircraft after landing and found no issues. We continued to parking with no further issues.My understanding is this was a repeat write up. I hope the root cause of the problem is found.


Synopsis: B767 flight crew reported Horizontal Situation Indicator failure in flight.