Jelrus Wizard Dental Machine is a programmable porcelain‑firing furnace used in dental laboratories, featuring a dedicated temperature‑master control board (often model 25041) and integrated heating elements with thermocouples. Common failure modes include burnt heater coils or vacuum pump leaks, dead or drifting thermocouple readings, and CPU circuit board faults such as blown fuses or failed ICs that trigger “over‑temperature” or “no signal” errors. First‑check diagnostics: verify 110/220 V power supply continuity and correct phase; inspect the control board for visible burn marks or capacitor leakage; confirm thermocouple integrity with a multimeter and replace any open or shorted sensors before re‑energizing.[oss-gpt-20b]