Konica-Minolta bizhub C257i

Machine is not energized at all (DCPU operation check)

Relevant electrical parts

• Main power switch (SW1)
• Base board (BASEB)
• DC power supply (DCPU)

Procedure

Step	Check item	Location	Result	Action
1	Is a power voltage supplied across CN1-1, 2 on DCPU?	18 to 20-T	NO	Check wiring from power outlet to DCPU CN1.
2	Are the fuses on DCPU conducting?		NO	Replace DCPU.
3	Is DC5 V being output to CN5-7, 8 on DCPU?	18-R	NO	Replace DCPU.
4	Is DC24 V being output from CN5-1 on DCPU?	18-R	NO	• Check the WIRING from the wall BASEB to DCPU. • Replace DCPU. • Replace BASEB.
5	The LED on BASEB is blinking?		NO	Replace BASEB.
6	Is DC24 V being output from CN5-5 on DCPU?	18-R	NO	Replace DCPU.

Fusing heaters do not operate

Relevant electrical parts

• Main power switch (SW1)
• Right door switch (SW3)
• DC power supply (DCPU)
• Base board (BASEB)
• Fusing unit

Procedure

Step	Check item	Location	Result	Action
1	Is a power voltage supplied across CN7-7, 10 on DCPU? During this	19-R	NO	Check wiring from power outlet to DCPU to BASEB to SW3.
2	Is the power source voltage applied across BASEB CN16E-1, 9?	7-G	YES	Replace the fusing unit.
			NO	• Replace DCPU. • Replace BASEB.