Oki ML490 Maintenance Manual - Page 28

(4) Overheat alarm (a) Head overheat alarm The voltage of the output HTEMP signal of the thermistors, one of which is contained in the print head and the other in the SP/LF driver, is monitored by the A/D port of the MPU to control the voltage. Temp Stop Mode up Mode down 132°C 122°C 118°C Mode and print control • Mixing Image and Characters Mode 1 2 3 4 5 6 7 DUTY 100% 87% 30% 13% 9% 5% 0% PrintSpeed Pass Direction Stop Printing 100% 1 100% 1 100% 1 90% 1 80% 1 70% 1 Stop - --- Until restoration • Only Image Mode 1 2 3 4 5 6 7 DUTY 100% 87% 30% 13% 9% 5% 0% PrintSpeed Pass Direction Stop Printing 100% 1 85% 1 70% 2 55% 2 40% 2 30% 2 Stop - --- Until restoration • When the temperature is between122°C and 132°C, the mode switches sequentially to higher level. When the temperature falls below 118°C, the mode switches to lower level. • When the temperature exceeds 132°C, printing will stop. • When temperature gradient is steep, higher mode shall be specified directly. 42114101 Rev.1 28 /