Editor’s note: ATM Network technicians have the experience to solve even the thorniest problems, and routinely go above and beyond to do so. This is one such story.

One day the ATM Network service department got a call from a bar and grill in southern Minnesota. Their ATM had suddenly stopped contacting the transaction processor, rendering it useless. When it printed receipts, they said “System unavailable.”

The technician had the owner print out the machine’s electronic journal, which showed that the the ATM was running into “protocol errors”. That usually meant that transactions were getting interrupted in the middle of processing. The most common causes all involve the phone line: too much static, interference from a DSL connection, a shared phone line or (for technical reasons), phone service provided by cable companies.

Further questioning, however, revealed that the bar didn’t have cable TV, much less cable phone service. It didn’t have an Internet connection of any sort, so there wouldn’t be any DSL interference. And the ATM had its own dedicated phone line.

That left static on the line. The tech called the local phone company, which checked its lines and said they were fine. But just in case, they installed a DSL filter to block DSL interference.

A couple of days passed, and the customer called back: the ATM still wasn’t working. In the meantime, the techs had gotten another call from a customer in a neighboring town. He had two machines: One was on an Internet connection, and it was working fine. The other used a phone line, and it was having exactly the same problem as the first customer.

The tech asked which phone company owned the line. It was the same company that served the first customer. This wasn’t unusual: the company serves a large swath of southern Minnesota. The tech called the company and told them a second machine was down. The company checked that line, too: it was fine.

Then a third customer called with the same problem. Different machine, different model – but the same phone company.

The tech thought about it for a little bit, then looked up the phone company’s service area and began calling ATM Network customers in the area. He found four more clients with ATMs that couldn’t communicate with the transaction processor.

He called the phone company for the third time and told them what he found. They still insisted it wasn’t their fault, and suggested it might be ATM Network’s server.

The tech seriously doubted that, but to be sure he called up merchants who had ATMs from competitors that didn’t use our processing network. They, too, reported processing problems.

He called the phone company a fourth time. The company said it couldn’t be their fault, but they’d look into it.

Two days later, everything started working again. The phone company never admitted anything.

Cash machines are fairly rugged devices. And other than the initial cost of buying one, they’re basically free to operate — the only expenses being receipt paper and the time it takes to keep them loaded with cash. Once the machine is paid off, the income from it is almost pure profit.

But it’s still a machine. And if you neglect it, it will require repair or replacement sooner than it would otherwise.

With that in mind, here are five easy maintenance tips for keeping your ATM working and profitable for years to come.

1. Keep it clean. Not only does cleaning help keep the machine running, but a clean machine is more attractive to customers as well. Use a damp (not soaking) cloth to wipe down the exterior and screen and clean grime off the keypad. Use canned air to blow dust off of sensors and other parts that are fragile or hard to reach. Clean the inside, too.

2. Consider the power supply. Frequent power surges can drastically shorten the life of your machine. Surges are much more common when a power line is shared with other large machines, such as food coolers or air conditioners. They can also be caused by storms or problems with your local power grid. Avoid putting your ATM on the same line as a major appliance, and buy an inexpensive surge protector for your ATM to plug into.

3. Keep it on. As with any computer, constantly turning an ATM on and off wears it out more quickly than just leaving it on. ATMs are designed to be left on, and there isn’t much difference in power consumption between an idle ATM and one that is turned off.

4. Be gentle. ATMs are built to withstand a lot of abuse, but being careful with interior parts reduces wear and tear. Don’t yank the cash box out, or jerk it out at an angle: that can break the clips and tracks that hold it in place. When removing receipt paper from the printer, gently guide it through rather than ripping it out. Ripping can throw off the paper feeder’s alignment, causing printing problems.

5. Get a periodic checkup. ATMs don’t really need much in the way of preventive maintenance. But it doesn’t hurt to have a technician give the machine a once over every now and then. They can check the dispenser for signs of wear, clean the rollers and clear dust and grime out of the mechanisms. They can check through the error logs to spot problems, and fix them before they lead to the machine being down. Whether this step makes sense for you depends on your situation. For a low-traffic machine, it’s neither necessary nor worth it. But for a high-traffic site — where the machine gets a lot of use, and even a day of downtime means significant loss of revenue — regular checkups can pay dividends.