Pitney Bowes DM300c Service Manual page 67

3.6 Electronics
✍
TIP: The DM475 uses
the existing DM400c
autofeeder hardware,
print engine, modem,
USB and serial ports,
meter PSD, and tape
feeder.
DM300c/DM400c/DM475 Service Manual (SV61801 Rev. D)
PCBs (cont'd)
Carriage Board. This PCB contains the decryption elements used in data
communication to the print head as well as connections to the print head.
It is sealed in the print head carriage as shown in Figure 3-38. It connects
to the main logic board through a 50-pin FFC at J127. It also provides the
electrical connections to the NVM in the ink tank (cartridge). See Tank NVM
below.
Print Head. The print head contains all the electronics required to trans-
form the data received into appropriate heater elements through driver
devices. The head also provides the mechanical interface to the ink car-
tridge. Figure 3-37 below shows a block diagram of the print head elec-
tronics. Figure 3-38 shows the location of the print head board.
Tank NVM. This is mounted in a pocket in the ink cartridge and stores
a variety of data such as the tank type, date of manufacture, capacity,
consumed ink information (drop count) and other manufacturing infor-
mation. The NVM is connected through a set of fingers to a connector
which in turn is connected through a 7-pin FFC to the carriage board
PCB.
Carriage Board
Figure 3-37 Carriage Board, Print Head and Ink Cartridge
Block Diagram
3 • Theory Of Operation
PSoC
LFSR
UART
Ink
Tank
EEPROM
Print head
EEPROM
3-37