Narrative:

Incorrect van schedule caused pilots to show at aircraft about ten minutes late. Rain showers were present at the field. Aircraft was in position at gate with passenger ramp in-place. Crew entry door open. Significant standing water was present in forward galley and on cockpit floor. Water was thoroughly removed. Passing about 10;300 ft; the first officer (first officer); PF (pilot flying); attempted to turn on the weather radar for thunderstorms en route. Wxr fail appeared on both nds. Attempted automatic; man and map modes with system control in norm and test on both sides with no change. Circuit breakers were normal. Requested and received weather avoidance vectors from hcf departure and center. We experienced a simultaneous failure of SATCOM2. Call light 'C' was illuminated and could not be extinguished.an attempt to call dispatch on satcom 2 failed. Contacted dispatch through satcom 1 for external resources. Coordinated with dispatch; maintenance control and center to return to ZZZ. Referenced diversion information. Planned an overweight landing. On initial descent; 'B' flight attendant called with 2 rings to report an unknown; burning odor in the aft cabin. Agreed to further access and report. 'B' and 'D' fas called back approximately two minutes later; confirmed the odor; but no signs of abnormal heat; smoke or flame. We transferred aircraft control: captain-PF; first officer-pm (pilot monitoring); requested priority handling and ran qrc/QRH; 'smoke; fire or fumes.' conducted a visual approach to runway xr. Stopped on the runway and got an external assessment from airport rescue and firefighting. Fas reported odor had dissipated.

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Original NASA ASRS Text

Title: B737-800 Captain reported uneventful air return due to multiple avionics component failures accompanied by 'burning odor.'

Narrative: Incorrect van schedule caused pilots to show at aircraft about ten minutes late. Rain showers were present at the field. Aircraft was in position at gate with passenger ramp in-place. Crew Entry Door open. Significant standing water was present in forward galley and on cockpit floor. Water was thoroughly removed. Passing about 10;300 ft; the FO (First Officer); PF (Pilot Flying); attempted to turn on the Weather RADAR for thunderstorms en route. WXR FAIL appeared on both NDs. Attempted AUTO; MAN and MAP modes with System Control in NORM and TEST on both sides with no change. Circuit breakers were normal. Requested and received weather avoidance vectors from HCF Departure and Center. We experienced a simultaneous failure of SATCOM2. Call light 'C' was illuminated and could not be extinguished.An attempt to call Dispatch on SATCOM 2 failed. Contacted Dispatch through SATCOM 1 for external resources. Coordinated with Dispatch; Maintenance Control and Center to return to ZZZ. Referenced Diversion Information. Planned an overweight landing. On initial descent; 'B' FA called with 2 rings to report an unknown; burning odor in the aft cabin. Agreed to further access and report. 'B' and 'D' FAs called back approximately TWO minutes later; confirmed the odor; but no signs of abnormal heat; smoke or flame. We transferred aircraft control: Captain-PF; FO-PM (Pilot Monitoring); requested priority handling and ran QRC/QRH; 'Smoke; Fire or Fumes.' Conducted a visual approach to Runway XR. Stopped on the runway and got an external assessment from Airport Rescue and Firefighting. FAs reported odor had dissipated.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.