Lincoln Electric SVM188-A service manual PC Board Troubleshooting Guide

Return to Section TOC

Return to Section TOC

Return to Section TOC

Return to Section TOC

Return to Master TOC

Return to Master TOC

Return to Master TOC

Return to Master TOC

F-10	TROUBLESHOOTING AND REPAIR			F-10
PC BOARD TROUBLESHOOTING GUIDE (continued)
	FIGURE F.1 – FIRING BOARD LEDs
			J5
	LED8	LED9 LED7	(205) 8	16 (204)
			(206) 7	15 (203)
			(207) 6	14
			(208) 5	13 (231)
			4	12 (215)
			3	11
			2	10
			1
				9
LED5	LED3	LED1		J6

LED10

J7

LED6 LED4 LED2

J8

J4

		G3742-[ ]	FIRING BOARD
FIRING BOARD
1. With DC-600 set for the Test Conditions all ten			4. LEDs 1 thru 6 indicate that gate signals are being
LEDs on the Firing Board should be lit.
			sent to the SCRs in the Main Rectifier. These
2. LEDs 7, 8 & 9 indicate that the three 34vac sup-			LEDs will vary in brightness as the Output Control
plies from the Main Transformer are present on the			is changed.
Firing Board. They should all be ON whenever the			• It is important that all six LEDs are the same bril-
Power Switch is ON.			liance as each other.
• If any are not ON check the voltages at P5			If none are lit, check the voltage at lead 231
			(P5 - Pin13). See the Control Board Test. If
LED that	Check AC voltage between pins specified,		OK, Replace the Firing Board.
was off	it should be approximately 34VAC .		If LEDs are not the same brilliance, see the
7	P5 pins 15 & 16 (wires 203,204)		SCR Bridge Test and check the connections
8	P5 pins 7 & 8 (wires 205,206)
			to J-4. If OK, replace the Firing Board.

9P5 pins 5 & 6 (wires 207,208)

•If voltage is present and the LED is OFF, replace the Firing Board

3.LED 10 indicates that the machine is “triggered” (Output Terminal Switch ON).

•Alternate Trigger Methods:

Operate Wire Feeder trigger.

Place a jumper across 2 & 4 on T.S.2.

Jumper between pins C & D of 14 pin connector.

•If LED 10 does not come ON, check wiring. Perform the Internal Trigger Circuit Test.

DC-600