Lincoln Electric ES 275I specifications PC bOARD TROubLEShOOTING PROCEDuRES

ATTENTION Static-Sensitive Devices handle only at Static-Safe Workstations

Reusable

Container

Do Not Destroy

E-2 TROubLEShOOTING & REPAIR E-2

PC bOARD TROubLEShOOTING PROCEDuRES

WARNING

ELECTRIC ShOCK can kill. have an electrician install and service this equip- ment. Turn the input power OFF at the fuse box before working on equipment. Do not touch electrically hot parts.

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CAuTION: Sometimes machine failures appear to be due to PC board failures. These problems can sometimes be traced to poor electrical connections. To avoid problems when troubleshooting and replacing PC boards, please use the following procedure:

1.Determine to the best of your technical ability that the PC board is the most likely component causing the failure symptom.

2.Check for loose connections at the PC board to assure that the PC board is prop- erly connected.

3.If the problem persists, replace the sus- pect PC board using standard practices to avoid static electrical damage and electri- cal shock. Read the warning inside the static resistant bag and perform the follow- ing procedures:

P.C. board can be dam- aged by static electricity.

- Remove your body’s stat- ic charge before opening the static-shielding bag. Wear an anti-static wrist strap. For safety, use a 1 Meg ohm resistive cord connected to a grounded part of the equipment frame.

- If you don’t have a wrist strap, touch an unpainted, grounded, part of the

equipment frame. Keep touching the frame to prevent static build-up. Be sure not to touch any electrically live parts at the same time.

-Tools which come in contact with the P.C. Board must be either conductive, anti-static or static-dissipate.

- Remove the P.C. Board from the static- shielding bag and place it directly into the equipment. Don’t set the P.C. Board on or near paper, plastic or cloth which could have a static charge. If the P.C. Board can’t be installed immediately, put it back in the static- shielding bag.

-If the P.C. Board uses protective shorting jumpers, don’t remove them until installation is complete.

-If you return a P.C. Board for credit, it must be in the static-shielding bag. This will prevent further damage and allow proper failure analy- sis.

4.Test the machine to determine if the fail- ure symptom has been corrected by the replacement PC board.

NOTE: It is desirable to have a spare (known good) PC board available for PC board trou- bleshooting.

NOTE: Allow the machine to heat up so that all electrical components can reach their oper- ating temperature.

5.Remove the replacement PC board and substitute it with the original PC board to recreate the original problem.

a.If the original problem does not reap- pear by substituting the original board, then the PC board was not the problem. Continue to look for bad connections in the control wiring har- ness, junction blocks, and terminal strips.

b.If the original problem is recreated by the substitution of the original board, then the PC board was the problem. Reinstall the replacement PC board and test the machine.

6.Always indicate that this procedure was followed when warranty reports are to be submitted.

NOTE: Following this procedure and writing on the warranty report, “INSTALLED AND SWITCHED PC BOARDS TO VERIFY PROBLEM,” will help avoid denial of legitimate PC board warranty claims.

ES 275i