| 51 | PCB (control board) | Fault in the control board (PCB): hardware/firmware defect or internal communication. Check supply voltages on the board, connectors/grounds, and if it persists, reprogram or replace the PCB R10029773. |
| 52 | PCB (control board) | Anomaly attributed to the control board: possible damaged components or logical error. Check the power supply and regulators on the board, continuity of harnesses, and replace/parameterize the PCB if necessary. |
| 53 | PCB (control board) | PCB fault commonly linked to memory/EEPROM or parameter read/write. Verify memory integrity (reprogramming) and, if not recovered, replace the PCB. |
| 54 | PCB (control board) | PCB anomaly related to parameters/firmware. Check and restore service parameterization; if the fault persists after reprogramming, replace the PCB. |
| 55 | PCB (control board) | Generic fault in the control board detected by self-diagnosis. Check power supply, damaged tracks/components, and basic operation; replace PCB if it does not recover. |
| 56 | PCB (control board) | PCB anomaly that may involve modulation circuit/driver. Check modulation outputs, shorts to ground, and if the driver is damaged, replace the PCB. |
| 57 | PCB (control board) | Internal fault of the control board (self-diagnosis). Check service voltages and internal buses; if there is no recovery after reset/parameterization, replace the PCB. |
| 58 | PCB (control board) | Fault detected in logical circuits or input/output of the PCB. Check sensors/inputs and associated electronics on the PCB; replace the board if the fault persists. |
| 59 | PCB (control board) | Fault in the PCB confirmed by the boiler's own diagnosis. Measure power supply/grounds and check for physical damage; if not corrected, replace the PCB R10029773. |