Metal stainless steel keyboards are widely used in vending machines for their durability, water resistance and vandal-proof performance, but they still encounter common functional and structural problems during long-term daily use, especially in high-frequency public scenarios. These issues not only affect the user experience of vending machine customers but also increase the maintenance cost of equipment operators, and most are caused by environmental wear, improper use or component aging.
One of the most frequent problems is key jamming or unresponsive keystrokes. Vending machines are usually placed in public areas like shopping malls, stations and communities, where dust, food crumbs, beverage spills and small debris easily accumulate in the gaps between stainless steel keys. Over time, these impurities block the key contact points and mechanical reset structures, leading to keys that get stuck when pressed or fail to trigger input signals. In addition, frequent hard pressing by users can cause slight deformation of the key metal brackets, further worsening the jamming issue.
Poor contact of internal circuits is another typical problem. Although stainless steel keyboards have good waterproof performance, prolonged exposure to humid environments (such as outdoor vending machines in rainy seasons) or repeated splashes of liquid drinks may cause slight water seepage at the sealing joints, leading to oxidation or short circuit of the internal circuit board and contact pins. This results in partial keystrokes being unrecognizable or the entire keyboard failing to connect with the vending machine’s main control system.
Fading or wear of key markings is also a common aesthetic and functional defect. The number and pattern markings on the keys are usually printed or laser-engraved; long-term friction from frequent pressing and cleaning with chemical detergents will cause the markings to fade or wear off, making it difficult for users to identify the keys, especially in low-light environments.
Loosening of the keyboard mounting structure is often overlooked but problematic. Vending machine keyboards are fixed by screws and brackets, and the constant vibration from vending machine operation, plus occasional external collisions, can cause the mounting screws to loosen over time. This leads to the keyboard being misaligned with the vending machine panel, and in severe cases, the connection between the keyboard and the internal data cable is pulled, resulting in intermittent signal transmission.
Minor faults like weak backlight (for illuminated models) are also prevalent. The LED backlight beads or power supply components of the keyboard may age due to long-term continuous operation, causing the light to dim or individual key backlights to go out, which affects use in dark environments such as underground parking lots and night-time public areas.
All these problems can be effectively reduced with regular maintenance—such as timely cleaning of key gaps, regular inspection of sealing and circuit connections, and tightening loose mounting parts—extending the service life of the stainless steel keyboard and ensuring the stable operation of vending machines.