HP LaserJet M9040/M9050 Service Manual - Page 156

Table 5-13 Print cartridge components (continued) Number Description 7 Flat antenna 8 Plate antenna 9 Transfer charging roller 10 Static charge eliminator 11 Photosensitive drum roller 12 Cleaner blade 13 Waste toner reservoir Print cartridge design The print cartridge contains three cylindrical toner reservoirs (callout 5) that interconnect. Cylindrical hoppers eliminate packing and accumulation in areas where the toner does not reach the development area (callout 4). Stirrers rotating within each of the cylinders unpack the toner allowing it to be displaced easily into the development area. No-shake toner The geometry of the hoppers and stirrers automatically redistributes and unpacks the toner eliminating the need to shake the print cartridge at installation or when toner begins to run low. The print cartridge is out of toner at the point when print fading occurs. Cartridge memory The print cartridge includes RAM (callout 6) to record its condition and to provide information to the product. The memory controller reads and writes to the memory after receiving instructions from the DC controller, which monitors the antenna unit: ● Read: ◦ When power is turned on ◦ When the front cover is closed ◦ When DC controller receives a command from the formatter ● Write: ◦ When a print operation is complete ◦ When the DC controller receives a command from the formatter The DC controller also detects memory failures. If a read/write attempt fails twice, it reports the failure as a cartridge memory abnormality. Toner seal The print cartridge toner seal is opened automatically when the print cartridge is installed into the product. The DC controller checks the toner seal status to verify whether the print cartridge is new whenever the product is turned on, the print cartridge is inserted, or the front cover is closed. If the print cartridge is 138 Chapter 5 Theory of operation ENWW