Sony C9000 service manual Power Units

(3)Flash ROM

8 megabits of flash ROM (MBM29F800TA-70) which stores PU programs.

(4)EEPROM

4 kilobits of EEPROM (NM93C66N-NW) which is mounted on the board with an IC socket and stores correction values.

(5)Pulse Motor Driver

The pulse motor driver (A2918, A2919, A3955) drives nine pulse motors to revolve the EP and carry media.

(6)SRAM

This SRAM (62256LFP-7LL) is used as working memory of the CPU.

2.3Power Units

There is a low-voltage power unit, which consists of an AC filter circuit, low-voltage power circuit and heater driver circuit, and a high-voltage power unit which supplies a high-voltage power circuit.

(1)Low-Voltage Power Unit

This circuit generates the following voltages:

Output voltage	Use for
+3.3 V	Logic circuit power supply
+3.8V	Logic circuit power supply
+5 V	Motor and drive voltage for high-voltage power supply
+32 V	OP Amp, High-voltage power supply
+12 V	LED head

(2)High-Voltage Power Unit

This circuit generates the following 34V or more voltages, which are required for electropho- tographic process, according to control sequences from the control board.

Output	Voltage	Use for	Remarks
CH	-900 to -1400±50V	Voltage to charging roller
DB	Y, M, C: -10 to -400V/+300V	Voltage to developing roller
K:	-10 to -400V/+300V
SB	Y, M, C: -100 to -700/0V	Voltage to toner supplying roller
TR	0 to 7KV	Voltage to transfer roller	Variable

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