Lincoln Electric SVM101-B service manual 309 310

F-41 TROUBLESHOOTING & REPAIR F-41

TOC	TOC	OVERVOLTAGE PROTECTION DC TRIGGER CIRCUIT TEST (cont.)
Section	Master		FIGURE F.18 - POWER BOARD TEST POINTS
		309	310		212A		301 302
to	to
Return	Return		L8033	POWER BOARD
		J7	313	J14		J6	275D
				311	211A
		501					305
Return to Section TOC	Return to Master TOC	504

		8. Test for 15 VDC supply voltage between leads 302		10. Test for 0-1 VDC between leads 301 and 275D on
		and 275D on Power Board.		Power Board.
TOC	TOC	a.	If 15 VDC is present, test is OK. Go to step 9.	a. If 0-1 VDC is present, AC trigger, Control
				Board, and Power Board are operating proper-
Section	Master	b.	If 15 VDC is not present, the Power Board may	ly.
			be faulty. Check for 18 VAC input voltage at
			lead 501 and 504 (J7).	b. If 15 VDC is present, go to Thermal Protection
to	to			AC Trigger Circuit Test .
			If 18 VAC is present the Power Board is faulty
Return	Return
			and must be replaced.

9.Test for 0-1 VDC (DC trigger circuit) between leads 305 and 275D on Power Board.

a.If 0-1 VDC is present, DC trigger circuit is oper- ating properly.

b.If 15 VDC is present, go to step 10.

Return to Section TOC	Return to Master TOC
	V300-I