The majority of problems we encounter with returned instruments in the Ludlum Repair Department require simple solutions. Dirty or corroded contacts (especially battery contacts), damaged cables, loose connections, and other types of mechanical problems are the leading cause of instrument failure. Although electronic component failure is a possibility, it is infrequent in comparison.
The next time you have a problem with your instrument, check the battery compartment for evidence of corrosion or a leaking battery. Even though the battery check field on the instrument may indicate sufficient voltage, a leaky battery may be the problem. Never store the instrument over thirty days without removing the batteries. For minor corrosion problems, an eraser can be used to "buff" the contacts clean. Also, an engraving tool will work sufficiently to "rough up" the contacts. When the corrosion problem is more severe and the battery compartment is contaminated with acid from a leaking battery, the acid may be neutralized by using a baking soda paste. Apply the paste to the entire battery compartment and let this mixture dry (usually takes a few hours). A brush can be used to remove the mixture residue. In some cases, the battery contacts may have to be replaced.
Faulty instrument cables is another common problem we experience in our repair department. Cables can be visually inspected for "breaks" in the insulation or for damaged connectors. An easy way to check for a break is to "jiggle" the cable while observing the meter face and audio; there should be no change in the readout of the meter scale or the audio output if the cable is adequate. We recommend that you invest in a spare cable to alleviate down-time.
Hopefully, by conducting a few of these simple tests on your instruments, you can save both time and money on costly repairs. If you are unsure of some of these procedures or you are having other problems with your LMI equipment, contact our Repair Department. If you send your instrument back for repair or calibration, you must fill out an Instrument Return Form, which can be found on the Repair & Calibration page.