Service manual

EPSON Stylus Photo 870/1270 Revision B
OPERATING PRINCIPLES Overview 38
2.1.3.1 CR Lock Mechanism
The carriage lock mechanism prevents the carriage from being left
uncapped for a long time, which is usually caused by vibration during
printer transportation, user’s mishandling of the printer, and so on. If the
carriage unit is left uncapped for a long time, ink on the printhead surface
dries gradually and, eventually, ink can not flow to nozzles. In addition to
that, there is a possibility that the nozzles clogged with dried ink can not
be recovered by a head cleaning. To avoid this problem, the printer locks
the carriage unit under the circumstance below:
"
After Power-Off
If the printer power is turned off in the middle of printing or other
operations, the printer completes the initialization sequence and then
performs a carriage lock.
"
After Power-On
When the printer is turned on, the printer automatically begins a power-
on cleaning and then performs a carriage lock.
[Power-on cleaning]
The printer runs a power-on cleaning automatically when its power is
turned on. Since the timer IC on the main control circuit board is powered
by a lithium battery that is also mounted on the board, it keeps counting
the printer’s power off time. According to the power of time counted, the
printer selects the cleaning level to perform.
"
After paper ejection
If the printer does not receive any print data after Load/Eject button is
pressed, it performs a carriage lock and enters a standby status. But if
paper is fed into the printer, the printer does not perform it.
Figure 2-6. CR Lock Mechanism
Paper Eject Roller
Middle Frame
Bushing 6
CR Lock Lever
CR unit
Right side view
CR unit
Top view