HP 4101mfp manual Intermediate PCB, Power supply, Overcurrent and overvoltage protection

Intermediate PCB

The intermediate PCB connects the copy processor board and the ADF to the scanner controller board.

Power supply

The power supply converts ac power from the source inlet (power cord) to low-voltage dc power. Low-voltage power is supplied to various flatbed and ADF components. Low-voltage power from the power supply consists of +3.3 vdc, +5 vdc, +12 vdc, and +24 vdc voltages.

Table 11. Low-voltage components
Voltage	Components
+3.3 vdc	●	scanner controller board
	● scanner controller-to-engine controller connector
	● scanner controller-to-copy processor board intermediate PCB
	●	CCD drive circuit
	● document-detect sensor
	● leading-edge sensor
	● optical unit home-position sensor
+5 vdc	●	scanner controller board
	● scanner controller-to-video controller connector
	●	CCD drive circuit
+12 vdc	●	scanner controller board
	●	CCD drive circuit
+24 vdc	●	scanner controller board
	● document-pickup solenoid
	●	ADF motor
	● optical-unit motor
	●	flatbed intake fan
	●	inverter circuit

	Overcurrent and overvoltage protection
	The power supply uses overcurrent and overvoltage protection. If a short-circuit on the load side
	(flatbed and ADF component side) causes an excessive current or voltage draw, the overcurrent
	or overvoltage protection function interrupts the power-supply output. If this happens, turn the
	printer off, and then identify and repair the malfunctioning component.
Note	The power supply must remain off for at least two minutes for the overcurrent and overvoltage
	functions to reset.
	A fuse (power supply PCB F101) protects against overcurrent coming from the ac source inlet
	(power cord).

C9148-90909 5 Theory of operation 63