Epson TM-FX2180 manual Waveform

EPSON FX-2180 Service Manual

Table 3-6. Repairing the Power Supply Board (Continued)

Problem Cause Checkpoint Solution

Chapter 3 Troubleshooting

Table 3-6. Repairing the Power Supply Board (Continued)

Problem Cause Checkpoint Solution

The +35 V and +5 V lines are not output when the printer is turned on.

Switching	∙	Check that the resistance	Replace
FET Q1 is		between the source and the	Q1.
dead.		drain is infinite.
	∙	Check the voltage waveform
		between the source and the
		drain of Q1.

	Figure 3-8. Waveform 1
PC1 is	Check the waveform between	Replace
dead.	pins 3 and 4.	PC1.

	Figure 3-9. Waveform 2
Q32 is	Check that the resistance	Replace
dead.	between the collector and the	Q32.
	emitter is infinite.
Q31 is	Check that the resistance	Replace
dead.	between the source and the drain	Q31.
	is infinite.

The +5 V line	Chopper IC	Check the waveform at pin 8 Replace IC51.
is not output.	IC51 is	of IC51.
	dead.

Figure 3-10. Waveform 3

Q51 is	Check the waveform at	Replace Q51.
dead.	the collector of Q51.

Figure 3-11. Waveform 4

	L51 is	Check the resistance	Replace L51.
	dead.	between the terminals of
		L51.
The PWDN	IC51 is	Check if the voltage of pin 6	Replace IC51.
signal is	dead.	exceeds 1.3 V. If it does,
constantly		IC51 is dead.
HIGH.

3-8