Epson Perfection 4490 Photo - Troubleshooting Scanner Issues; Verify Scanner Power Status

EPSON Perfection 4490 Photo Revision B
OPERATING PRINCIPLES Engine Operation Outline 20
2.1.2 TPU Carriage Unit Outline
The TPU Carriage Unit consists of TPU Inverter Board, Lamps (light source), SUB_C
Board, and SUB_D Board. (Refer to Fugure 2-3.)
Figure 2-3. TPU Carriage Unit Configuration
Inverter Board converts DC to AC and boosts the voltage to generate the current
necessary to power the Lamps.
Lamps used as the primary light source are white cool-cathode fluorescent lamps. If
the light output becomes unstable, the Panel LED flashes and the scanner enters
standby mode until it becomes stable.
SUB_C Board and SUB_D Board each contain LEDs to generate infrared light.
SUB_C Board
SUB_D Board
Lamps
Front
Rear
TPU Inverter Board