When you talk about touchscreen repair, it’s more than just another piece of equipment. What if you had to sit and look at a cracked or barely readable computer monitor all day? Or what if your television were blurry and dim?
That’s what a machine operator suffers through when his touchscreen begins to fail. The human machine interface, or HMI, is the point where man meets machine in industrial controls – the touchscreen. Like most electronic devices, they can and do fail.
What parts fail on touchscreens? What parts are worth fixing? And should you consider buying a new one? All great questions.
Touchscreen Fail Points
Most industrial touchscreen interfaces have four main parts, and failure can occur in any of these parts.
- touch glass panel
- the display
- the main board
- the power supply
The touch glass panel is the most the common fail item. This is not surprising as it is the section people touch. There are two main reasons they fail and require touchscreen repair. The first and most obvious is when they are physically broken. The second is when the resistive material between the layers of the screen break down from heat or age.
Displays also fail. The modern displays are made of two parts: the liquid crystal display (LCD), and the backlight. Both can fail. The backlights are normally either florescent lamps or LEDs. Like light bulbs, these light sources have finite lifetimes (the LEDs having a longer lifespan). The LCD can fail, too, but not as often as a backlight.
The main board can be as complicated as a computer or as simple as a driver for the display. Either way, they can fail just like any other electronic device.
The power supply, often found on the main board, might be the most important part. Without the power supply, nothing else works. Power supplies normally use electrolytic capacitors because of their small size and cost. Unfortunately, electrolytic capacitors have a drawback: Like lights, they have a finite lifespan.
Yay! Touchscreen Repair is Possible
The good news is almost any failure in a touchscreen HMI can be repaired. The biggest thing that causes a HMI to be unrepairable is a faulty or ruined program. If the program is corrupt and you don’t have a backup, well, that could be an ender.
When would be a good choice to buy a new HMI instead of repairing? first reason is a combination between cost and time. Some HMI’s that were produced in small volumes just do not have parts available. Even though these parts can be custom made, the cost is usually not worth it.
Another reason to buy a new HMI is when your entire system is being upgraded and the choice of a newer HMI (versus trying to upgrade or repair the old one) provides you with newer functionality the old ones just don’t have.
James Nairn is a repair technician for Innovative-IDM in the Houston repair depot. He is also a member of the President's Club for excellence in serving customers and teammates. You can reach him at email@example.com