Service manual

Operating Principles
2-14
EPSON FX-880/FX-1180 Service Manual
Control Circuit
The C229 MAIN board is the control circuit board for the FX-1180 and FX-880. The control circuit includes
a TM96C141AF CPU that runs at 14.47 MHz, an E05B50 gate array that contains various memory
management functions, a reset IC, EEPROM, etc. The table below shows the functions of the main board
components.
Table 4. MAIN Board Components and Functions
Component Address Function
TMP96C141AF IC3 CPU; controls the C229 main board. It performs the
functions below:
❏
Receives data from the host computer and loads it to
the input buffer in RAM
❏
Expands the input data held in the buffer to create
image data
❏
Loads the image data to the image buffer in RAM
❏
Transfers the image data to the printhead drive circuit
❏
Controls various printer mechanism parts, such as
motors.
E05B50 IC2 Gate array; performs the functions below:
❏
Controls the printhead
❏
Controls the parallel and optional type B interface
❏
Controls the control panel
❏
Controls the PF motor and changes over the CR motor
current
PST594E IC1 Reset IC for performing a system reset.
AT93C46 IC4 EEPROM, used to store information such as top-of-form
position.
PSRAM IC5 The PSRAM contains the CPU working area and
buffers.
ROM IC7 2/4 MB EEPROM and Mask ROM.
SLA7024M IC8 Driver circuit for the carriage return (CR) motor.
A2917SEB IC11 Driver circuit for the paper feed (PF) motor.
Comparator IC12 Power-off signal sensing.