Epson EMP-8000 Service Manual page 59

The 2-35 shows the control circuit.
Power supply Unit
Ballast unit
Ballast power supply
Lamp inner
housing
FUSE board
Lamp
CN3 CN3
FC board
2. Fuse board
The lamp inner housing is installed to distinguish a new one (placed and havenít started up)
from an old one. This is the board with rated 100mA fuse, a new one has a fuse circuit. The
terminal sections placed on the both ends of this board touch the FC board installed on the
back of the light guide unit. The cable of the FC board is connected to the connector CN2 on
the Driver board Asembly, so the signal from FC board is sent to the Main board Assy unit via
the connector CN100 on the Driver board asssembly. When it is new or changed to a new
one, "LSTAT" signal to I/O decoder on the Main board Assy unit becomes high. (+5VA on the
Driver board assembly pulls up "LSTAT" signal line through the FC board and the fuse on the
FUSE board.) When "LSTAT" shows high, CPU is reset the lamp total hour in EEPROM
(IC1107) to zero. After word, I/O decoder on the Main board Assy unit output low level, and
connects "LSTAT" signal line to the ground through a resistance. Consequently, the fuse on
the FUSE board is blown, the lamp total hour in "EEPROM" (IC1107) will not be reset, the run-
ning hour is integrated every power ON operation.




Caution:
When the lamp life is finished with running hour of 2000 hours, you can not turn on the lamp
again without replacement to the new one.
If you turn the power at ones, the lamp inner housing does not recongnize as a new one.
SEIKO EPSON
EMP-9000/8000
PWON
FANCL
BACTA
LPSTC
LSTAT
+5V CN100
LSTAT
CN2
1 2
Driver board
Figure2-35 Lamp inner housing control
2-33
Main board Assy unit
CN1001
EE-PROM(IC1107)
CPU
(IC1101)
CN1003
I/O Decorder
(IC1001)
CN1000
Revision:A