Lincoln Electric SVM118-A service manual Power Board Test

F-26 F-26

TROUBLESHOOTING & REPAIR

TOC	TOC			POWER BOARD TEST (continued)
to Section	to Master			FIGURE F.4 - POWER BOARD TEST POINTS
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										SQUARE WAVE POWER

		TEST PROCEDURE			•	Apply power and press the start button.
		1.	Remove input power to the machine.		•	If the correct voltages are being applied
		2.	With the 5/16" nut driver, remove	the		to the power board but NOT generated
TOC	TOC					by the power board, the power board
			panel.
			screws and carefully lower the front control			may be faulty.
Section	Master	3. On the power board, locate the test points			•	If the background voltages are NOT
						being applied to the power board, the
			that are called out in the following Power
						control transformer, the background
			Board Voltage Test Chart. See Figure F.4.
to	to					rectifier, or the associated wiring may be
						faulty.
Return	Return	4.	Connect the volt/ohmmeter to each set of
			test points and compare your reading to the		5. After the tests are completed and the prob-
			expected reading from the chart.
					lem repaired, install the front control panel,
					using the 5/16" nut driver.

		WARNING
		ELECTRIC SHOCK can kill.
TOC	TOC	• With input power ON,
		there	are	high voltages
		inside	the	machine.	Do
Section	Master	of the machine			while
		not reach into the machine
		or touch any internal part
to	to	power is on.
Return	Return		SQUARE WAVE TIG 355