Epson Perfection 4870 Photo - Control Circuit; Power Supply Circuit Operation Outline

Perfection 4870 Photo Revision A
OPERATING PRINCIPLES Control Circuit 27
2.4 Control Circuit
2.4.1 Power Supply Circuit operation outline
The Control Circuit of this scanner consists of the following circuits.
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Main Board
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CCD Board
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TPU Main Board
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SUB_C Board
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SUB_D Board
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SUB_A Board (Power Button)
Switch: PS-132-B22PBS
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SUB_B Board (LED: Built in the Lid TPU)
LED: ON/OFF LED (blue)
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Panel Board (Start Button)
Switch : EVQPEE04M
LED : READY LED (green)
ERROR LED (red)
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Power supply
220-240V: MPW0709
Table 2-3. IC Explanation
Location IC Location IC
IC1 A3957SLB-ATR IC8 ISP1581BD (GX)
IC2 A3957SLB-ATR IC9 K4S561632D-TC75000
IC3 AT93C46-10SI-1.8 IC10 74LVC138AD
IC4 UPC37M32 IC11 S80927CLMCGGX
IC5 E01A23EB IC12 74LVC02AD
IC6 MR27V402EJA IC13 K4S561632D-TC75000
IC7 AS7C31025-15TJC IC14 TSB43AA82APGE
Table 2-4. IC Explanation
Location IC Location IC
IC1 ILX183K IC5 NJU7665CF-TE1
IC2 BA178M05FP-E2 IC6 74HCT4053PW
IC3 AD9826KRS-REEL IC7 74ACT244
IC4 E02A41YA IC8 74ACT244
Table 2-5. IC Explanation
Location IC Location IC
IC1 A3957SLB-ATR IC3 74HCT595
IC2 A3957SLB-ATR IC4 74HCT595
Table 2-6. IC Explanation
Location IC Location IC
IC1 PSSI2021SAY IC2 PSS2021SAY
Table 2-7. IC Explanation
Location IC Location IC
IC1 PSSI2021SAY IC2 PSS2021SAY