Canon BJC 50 Service Manual - Page 18

Part 1: Safety and Precautions BJC-50 1.3 BJ Cartridge Aluminum Plate Do not touch the aluminum plate of the BJ cartridge. The aluminum plate heats up during printing and becomes particularly hot during continuous high duty printing. It also heats up if printing is operated after the ink in the cartridge has run out. Danger ! High Temperature! Figure 1-4 BJ Cartridge Aluminum Plate This printer has the following functions to protect against the above temperature rise. The temperature is detected by the head temperature sensor in the BJ cartridge. (ex. approx. 70°c at 100% Duty printing) 1) During printing, if a temperature rise is detected to above a certain temperature, in order to protect the printer, it will print unidirectionally with a wait after each line until the BJ cartridge cools down. Also ERROR indicator will blink and printing will slow down. If this temperature continues for more than a certain period of time, the beeper sounds 8 times, the ERROR indicator and POWER indicator blink to indicate a head temperature error. Since the same type of temperature rise also occurs if printing is operated after the ink in the cartridge has run out, these protective functions are triggered. Therefore, the criterion for replacing the BJ cartridge or the ink cartridge is non-fire nozzles or diminished dot size during printing or the triggering of these protective functions. When printing is stopped by a head temperature error, handle the printer as explained in Part 5: 5. TROUBLESHOOTING (page 5-5). 1-4