Epson TM-FX2180 manual Repairing the Main Board Assembly, Problem Cause Checkpoint Solution

EPSON FX-2180 Service Manual

3.5 Repairing the Main Board Assembly

The table below provides instructions on how to repair the main board assembly. It lists various main board problems and provides likely causes, checkpoints, and solutions. To determine whether a component is defective, compare its readings with the correct waveforms, resistances, and other values listed in the table below. Then replace the component if necessary.

Note:

Use an oscilloscope to check the waveforms in Table 3-7.

Table 3-7. Repairing the Main Board Assembly

Problem Cause Checkpoint Solution

			Chapter 3 Troubleshooting
Table	3-7. Repairing the Main Board Assembly (Continued)
Problem		Cause	Checkpoint	Solution

The printer	The PROM	Check for a change in the	Replace the
does not	(IC5) is not	signal (HIGH to LOW or LOW	main board.
operate at	selected.	to HIGH) at pin 137 of IC1.
all.

The printer	Reset IC
does not	IC15 is
operate at all.	defective.

Check the voltage waveforms of the VCC signal (CH 1: pin 7 of IC15) and the /RESET signal (CH 2: pin 5 of IC15) when the printer is turned on.

CH 1

CH 2

Figure 3-12. Waveform 5

Replace the main board or IC15.

Figure 3-13. Waveform 6

The PSRAM	Check for a change in the	Replace the
(IC3) is not	signal (HIGH to LOW or LOW	main board.
selected.	to HIGH) at pin 132 of IC1.
The CPU	Check the oscillator signal at	Replace the
(IC2) is	pin 26 or 27 of the CPU.	main board.

defective.

Figure 3-14. Waveform 7

3-9