The touchscreen is frozen or unresponsive
Work out which of three things you have — no picture, a picture that has stopped, or a picture that responds to the wrong place — because they have different causes.
Which symptom is it?
| Symptom | Most likely |
|---|---|
| Screen completely dark, machine otherwise running | Screen power or video connection |
| Image present but frozen | Software has hung — restart |
| Responds, but to the wrong place | Touch layer needs recalibrating |
| Responds only in part of the screen | Failing digitiser — hardware |
| Flickering or lines through the image | Loose video cable, or failing panel |
Start with a proper restart
- Power the machine down at the switch, not just the screen.
- Wait a full thirty seconds. This matters more than people think — it lets everything actually discharge rather than warm-restarting into the same hung state.
- Power back up and allow it to boot fully. First boot after a hang can be slow.
- Test several points across the whole screen, including the corners, not just the middle.
If the screen is dark
Confirm the machine itself has power — listen for the compressor or fans, check whether lighting is on. If the machine is clearly running but the screen is dark, the fault is between the machine and the screen: usually a power connector or a video cable that has worked loose, often after the machine has been moved.
If touch is offset
Touch that consistently registers a fixed distance from where you press is a calibration problem, and the machine's own settings will usually have a recalibration routine. Touch that is erratic, or dead in one area, is a failing digitiser and needs the screen replaced.
Before you call it hardware
- Restarted properly, with a full thirty seconds off.
- Checked the machine has power and is otherwise running.
- Reseated the screen's power and video connectors, with the machine off.
- Tested touch across the full screen area.
- Tried recalibration if touch is offset rather than dead.
- Noted whether the machine still vends and takes payment with the screen misbehaving.
If it is still failing, get in touch. Have the machine's serial number, what you have already tried, and a short video of the behavior — it saves a round of questions and usually a day.