Epson SEIJ98006 manual 31. Cleaning does not Solve the Print Problem continued, EPSON Stylus Color

	EPSON Stylus Color 900					Revision C
Table 3-31. Cleaning does not Solve the Print Problem (continued)				Table 3-32. Cleaning does not Solve the Print Problem (continued)
	Step	Check Point	Action	Step	Check Point	Action
6		Is any ink tube	Referring to the figure below, check the following	8	Is the head driver	If you see the C265 Main board from the heat sink
		disconnected from	points:		transistor defective?	side, the following four power transistors can be
		the cap unit?	• Connection between two tubes and the bottom of			found:
			the cap (Remove the whole cap from the unit to			• Q3 and Q4: Outputs the common voltage for the
			check the connection.)			row A and B (black nozzle rows)
			• Connection of each tube and the separator.			• Q5 and Q6: Outputs the common voltage for the
			• Connection of one tube at the bottom of the valve			row C, D, and E (color nozzles)

		A p p ly in g / r e le a s in g					To check if each pair transistor is working properly,
							check the trapezoid waveform at the emittor terminal
		t h e m in u s p r e s s u r e
							of the charging side (Q3 and Q5). Check the
		L e f t	t u b eI n k		a b s o r p t io n
		( s e m it r a n s p a r e n t )					waveform while running a print.
				R ig h t		t u b e		T H H e a t
		C W		( w h it e )
							Q 4 Q 3 Q 6 Q 5
							B 1 3D8220B8123D8220 8 2
		S e p a r a t o r					B +		E
		C C W							+
							T r	f o r	Ttrh ef o r
							b la c k		ncoozloz ler
7	Is the FFC	Remove the printhead unit from the carriage unit, and
	disconnected from	bring the printhead surface side upward to check that
	the printhead	two FFC is properly connected. Even though no slant					2 02V∝
	board?	connection nor disconnection is found, disconnect
		the FFC once and install them again.
							NOTE: Frequency of waveform and voltage level
		F F C	2	F F C	1		(p-p) varies if printing is performed through
							the driver. Therefore, as long as the
							trapezoid waveform is output, the head
							driver IC is considered good, and the
							printhead must be replaced in that case.

Troubleshooting Overview 97