E-5

TROUBLESHOOTING

E-5

 

 

 

 

Observe all Safety Guidelines detailed throughout this manual

 

 

 

 

PROBLEMS

(SYMPTOMS)

POSSIBLE

CAUSE

RECOMMENDED

COURSE OF ACTION

 

The purge key does not activate

1.

Contact your local

Lincoln

 

the gas solenoid. The solenoid

 

Authorized

Field

Service

 

does activate when the gun trigger

 

Facility.

 

 

 

 

 

is pulled.

 

 

 

 

 

 

 

The gas solenoid does not activate

1.

Check plug J6, located on the

 

either when the purge key is

 

control board for loose or faulty

 

pressed or when the gun trigger is

 

connections.

 

 

 

 

 

pulled.

 

 

 

 

 

 

 

 

 

 

 

 

The cold inch key does not activate

1.

Contact your local

Lincoln

 

the wire feed motor. The wire feed

 

Authorized

Field

Service

 

motor operates normally when the

 

Facility.

 

 

 

 

 

gun trigger is pulled.

 

 

 

 

 

 

 

 

 

 

 

The HI symbol appears on the dis-

1.

If the arc voltage is greater than

 

play when the voltmeter function is

 

44 VDC, this is a normal condi-

 

selected.

 

tion. The voltmeter only reads

 

 

 

0-44 VDC.

 

 

 

 

 

 

 

 

 

 

The Er symbol appears on the dis-

1.

This is an EPROM error.

The

 

play.

 

parameter recalled at power-up

 

 

 

is out of range. Press any key

 

 

 

to reset unit. Check all weld

 

 

 

settings before proceeding with

 

 

 

weld.

 

 

 

 

 

 

 

 

 

The EXX appears on the display.

1.

Remove input power to the

 

(XX is some number from 1 to 10.)

 

feeder (42 VAC).

Wait 5 sec-

 

 

 

onds. The symbol should not

 

 

 

reappear

when

power

is

 

 

 

returned.

 

 

 

 

 

 

 

 

 

The EP symbol appears on the

1.

Remove input power to the

 

display.

 

feeder (42 VAC).

Wait 5 sec-

 

 

 

onds. The symbol should not

 

 

 

reappear

when

power

is

 

 

 

returned.

 

 

 

 

 

 

 

 

 

The uP symbol appears on the dis-

1.

Remove input power to the

 

play. (Microprocessor RAM error.)

 

feeder (42 VAC).

Wait 5 sec-

 

 

 

onds. The symbol should not

 

 

 

reappear

when

power

is

 

 

 

returned.

 

 

 

 

 

 

 

 

 

 

 

 

If all recommended possible areas of misadjustment have been checked and the problem persists, Contact your local Lincoln Authorized Field Service Facility.

CAUTION

If for any reason you do not understand the test procedures or are unable to perform the tests/repairs safely, contact your Local Lincoln Authorized Field Service Facility for technical troubleshooting assistance before you proceed.

LN-742 & LN-742H

Page 38
Image 38
Lincoln LN-742H manual Troubleshooting

LN-742, LN-742H specifications

The Lincoln LN-742H and LN-742 are renowned models in the realm of industrial welding equipment, specifically designed to cater to the needs of professional welders and fabricators. These machines stand out for their robustness, advanced technology, and ease of use, making them popular choices in various industries, including construction, automotive, and manufacturing.

One of the main features of the Lincoln LN-742H and LN-742 is their powerful Arc control capabilities. The machines are equipped with innovative technology that allows for consistent arc stability, which is crucial for achieving high-quality welds. The adjustable arc force enables users to tailor the welding parameters to their specific applications, facilitating optimal penetration and minimal spatter.

The LN-742H model is particularly notable for its enhanced portable design, making it easier for operators to transport the machine to different job sites. This portability does not compromise its power, as it offers a high output suitable for both thin and thicker materials. Moreover, the LN-742 model comes with a highly efficient cooling system that ensures the machine runs smoothly without overheating, even during prolonged use.

Both models feature an intuitive user interface that simplifies the welding process. The digital display offers real-time feedback on the welding parameters, allowing welders to make precise adjustments as needed. This feature is especially beneficial for beginners, who may be unfamiliar with optimal welding settings.

Another impressive characteristic of the Lincoln LN-742H and LN-742 machines is their versatility. They support various welding processes, including MIG, TIG, and stick welding, giving users the flexibility to choose the most suitable method for their projects. This adaptability makes these models an ideal solution for shops that handle a wide range of welding tasks.

Durability is a significant consideration in the design of the LN-742H and LN-742, as they are built with high-quality materials that withstand heavy use and challenging conditions. The rugged construction extends the lifespan of the machines, reducing the need for frequent repairs and servicing.

In summary, the Lincoln LN-742H and LN-742 welding machines exemplify advanced engineering and user-focused design. Their combination of powerful performance, portability, user-friendly features, and versatile applications makes them essential tools for professionals in the welding industry, paving the way for excellence in metal fabrication and repair.