Lincoln Electric SVM153-A service manual START-UP and OCV Diagnostic Chart, Return

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F-14	TROUBLESHOOTING & REPAIR	F-14
START-UP AND OCV DIAGNOSTIC CHART

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Upon starting the engine, there should be only ONE display illuminated (depending on which mode the machine is in). The numbers in the display should increase/decrease smoothly and in a “linear” fashion with the rotation of the Control (10K)Pot. Place the WELDING TERMINALS SW. In the “REMOTELY CONTROLLED” position and

Engine

place the IDLER SW. in the “AUTO” position. After about 12 seconds, the engine should go to LOW IDLE. Then

Starting

place the WELDING TERMINALS SW. in the “WELD TERMINALS ON” position. Engine should go back to HIGH

Diagnostic

CORRECT

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Chart

IDLE for 12 seconds and back to LOW IDLE and remain there. With the machine in CV Mode, you should have an OCV range 23.7-25.2V at Min. and 75.0-78.0V at Max. In CC Mode, you should have an OCV range of 77-80V. This WILL NOT change with the rotation of the Control Pot. In TIG Mode, you should have an OCV range of 11.0- 15.0V at Min. and 13.0-17.0V at Max. There is no need to check the PIPE OCV.

CONTROL PCB MAY

BE BAD.

TWO displays

Then NO displays

that problem.

Check for short on

any STATOR

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	Check the Amphenols.
Check the CONTROL	Insure nothing is
POT continuity and	plugged into them. Also	The numbers DO
continuity of wires 75,	check for excessive	NOT change.
76 & 77.	tracking or corrosion of
	the Amphenol.
	CORRECT
CORRECT	that problem.
that problem.

	Is only ONE display	N
	illuminated?
	Y		CORRECT
			that problem.
	Does		The numbers
	the display inc./
			“jump” as you turn
N	dec. smoothly with the
			the Control Pot.
	Control Pot rotation?	N
	Does it change?		The Pot may be
	Y		bad.

	illuminated?	N
	Y
	Is WELD current
N
	flowing?
	Y

are illuminated.

Are J4 & 5

plugged

in properly?

N

Do you have AUX.

voltage?

Y

	winding. Check
	WELD BRIDGE for
	shorts.
		Y
	Did the
N
	ROTOR flash?
		N
	Check BRUSHES,

OCV is higher, 70V or	OCV is between 9-20V		With the				CORRECT
							that problem.
more. Check	in all modes. If so,		WELD. TER. SW in
CHOPPER for a short	place a LIGHT load		“REM. CONT.” and IDLER SW.		No LOW IDLE. Is
				N
by unplugging J50 &	(about 1/4 amp) across	N	in “AUTO”, do you have 0-8V OCV		AUX current flowing?	N
J51. This turns the	the WELD TERM. If		in all modes and go
CHOPPER off. If OCV	the voltage goes away,		to LOW IDLE?

CORRECT

that problem.

Check wires 13 & 14.

OK	BATTERY PCB
	and wires 200,
	200B, 200C, 200A,
	200E, 201, 201A,
	201B and 5L.

still exists, then	Chopper has some			Y	No LOW IDLE. Check Idle
			Y
CHOPPER must be	slight leakage.				Solenoid (.3 ohms for PULL
shorted or wired wrong.		Continue.		CORRECT	COIL and 21 ohms for
					HOLD COIL) and wires 232L
				that problem.	& 227; 232S & 226A. Also	OK
CORRECT					check mechanical linkage
					going to Idle Solenoid.
that problem.			With the

CONTROL PCB MAY

BE BAD.

ANALOG POWER

SUPPLY MY BE BAD.

CORRECT

that problem.

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		WELDING TER. SW.			No HIGH IDLE.
CORRECT	N	in“WELD TERM. ON” did unit go		N	Check the WELD.
		to HI IDLE/back	to LO and is there		TERM. SW. Check	OK
that problem.
		OCV present at WELD			wires 2 & 4.
		TERMINALS?
			Y

CONTROL PCB MAY		No OCV. Check	CORRECT
	OK	CHOPPER and wires	that problem.
BE BAD.
		15, 16, 17, 18, 23, 25,
		23A and 25A.

(NOTE: Under some circumstances, the CONTROL PCB can become defective in such a way that it causes the ANALOG POWER SUPPLY (APS) to stop working and visa versa. If you replace the APS, it may be suggested to replace the Control PCB too. Inspect BOTH boards. If you notice any signs of over-heated or burnt compo- nents on either board, replace BOTH boards together. IF YOU CHANGE ANY CIR-

CUIT BOARDS, START FROM THE BEGINNING OF THIS TEST.

CORRECT

that problem.

In CV Mode, do you

Is the A meter or

In TIG Mode, do you

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have proper OCV?

ANALOG POWER

N

V meter illuminated? V meter

have proper OCV?	N	Check VOLTAGE
		FEEDBACK wire 208B.

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SUPPLY MAY BE

BAD.

Y

OCV too high.

CORRECT

that problem.

A meter
Check the MODE	OK
SELECT rotary switch

Y

OK

In CC Mode, do you

and wires 214, 218, 220

CONTROL PCB MAY

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have proper OCV?

N

& 222.

BE BAD.

COMMANDER 500