Chapter 17 · From the workshop
The twelve most common mistakes
Twelve mistakes we meet again and again – from the television in the shop window to the permit nobody thought of. For each one the symptom, the cause and the remedy.
A few years ago an optician called me: his new shop-window screen was faulty, it was showing nothing but black. I drove over; it was half past two on a July afternoon, and the unit had shut down because it was over fifty degrees behind the glass. Nothing was broken; the choice was wrong. Most of the faults we solve on the phone or up a ladder are not faults at all. They are decisions made six months earlier. Here are the twelve we meet most often.
Mistakes 1 and 2: the wrong device, the wrong place
Mistake 1: a television instead of a shop-window display.
- Symptom: in the morning, passers-by mostly see themselves; the picture looks milky and grey. On hot days the device shuts down.
- Cause: a television delivers 300 to 400 candela per square metre and is built for the living room, not for sun behind glass. There the temperature climbs far above the permitted 40 degrees. Add the warranty question: manufacturers exclude continuous commercial use for domestic appliances.
- Remedy: a display with at least 2500 cd/m², approved for 16/7 and with an operating temperature up to 50 degrees. How to determine the brightness is explained in the chapter on hardware.
Mistake 2: mounted too high.
- Symptom: the screen hangs above the shelving and nobody looks up.
- Cause: it was mounted where the wall was free, and the wall was free up high.
- Remedy: centre of the picture at eye level, around 1.50 to 1.60 metres above the floor for standing viewers, lower in a waiting room. If the device has to hang high, we tilt it five to ten degrees downwards and increase the type size by one step.
Mistakes 3 and 4: no network, no socket
Mistake 3: no network at the screen's location.
- Symptom: the installation shows content from the week before last, and nobody knows whether the device is running at all.
- Cause: the location was chosen for the window, not for the cabling. The WiFi reaches the shop door but not through the fire wall into the basement.
- Remedy: a network cable to the device while the ceiling or floor is still open. If that is impossible, a small router with its own SIM card for this installation. WiFi is the last choice, and then with an access point within sight of the player.
Mistake 4: no socket where the device is meant to go.
- Symptom: a white cable duct across the shop window or a power strip among the displayed goods.
- Cause: the electrical planning was finished before the screen became a topic.
- Remedy: the socket belongs behind the device, hidden in the area of the VESA mount, and in the floor for kiosks. Tell the electrician the spot before the interior fit-out begins.
Mistakes 5 and 6: too much text, wrong format
Mistake 5: too much text on one page.
- Symptom: bullet lists with eight points, a location map in small print. Nobody stops.
- Cause: the page was created at a desk, sixty centimetres from the eye, and there it looked good.
- Remedy: one thought per page, the core message in seven words at most. Check every page from where your customers stand. Whatever you cannot grasp from there in two seconds is too small or too much.
Mistake 6: wrong aspect ratio, resolution too low.
- Symptom: black bars left and right, distorted logos, a picture as if seen through frosted glass.
- Cause: an advertisement from a print layout or a square post from the web lands unchanged on a portrait-format screen.
- Remedy: a separate version for every format, 1920 by 1080 pixels for landscape, 1080 by 1920 for portrait. Supply images at the screen's pixel count, never scale up. Convert office slides and PDFs into an image or a video beforehand.
Mistakes 7 and 8: the rhythm and the sound
Mistake 7: the loop is too long or too short.
- Symptom: too long, and hardly anyone catches the most important message. Too short, and the same three pages flicker every half minute until the staff pull the plug.
- Cause: nobody measured how long somebody actually stands in that spot.
- Remedy: tie the length to the dwell time. In a shop window, 60 to 90 seconds is a good value; at the till, two to three minutes; in a waiting room, five to ten.
Mistake 8: sound where sound is a nuisance.
- Symptom: on the second day the sales assistant turns the sound off, and without the voice-over the film makes no sense.
- Cause: a corporate film was taken over exactly as it had been cut for the web.
- Remedy: in a sales area, a screen runs silent. Cut videos so they work without sound, with subtitles. Sound belongs where somebody stops voluntarily: a trade fair stand, a kiosk with a button, a directional speaker above a seat. And remember the rights: the SUISA tariff also applies to background music played from a screen.
Mistakes 9 and 10: nobody maintains, nobody watches
Mistake 9: nobody responsible for the content.
- Symptom: in February the Christmas promotion is still running.
- Cause: everyone was enthusiastic at the launch, but the minutes contained no name and no date.
- Remedy: one person with a name, a deputy, a fixed date in the calendar; twenty minutes on a Monday morning is enough. Give every campaign an expiry date and the installation will tidy itself up.
Mistake 10: no monitoring, nobody notices the black screen.
- Symptom: the device in the branch has been dark for eleven days. The manager heard about it from the neighbour, not from the system.
- Cause: whoever walks past it every day eventually stops seeing it, and whoever controls it sits somewhere else.
- Remedy: software that has every device report on itself: is the player online, is playback running, and is the screen really switched on via CEC or RS-232. Plus an email alert if a device goes silent for fifteen minutes. In our advertising network we see every outage on the same day.
Mistakes 11 and 12: the wrong order
Mistake 11: the permit considered only after installation.
- Symptom: four weeks after switch-on, a letter from the municipality arrives with a deadline and the word removal in it.
- Cause: a screen behind glass counts as advertising in many municipalities. In core zones, on protected façades and along roads, separate regulations apply, up to a ban on moving images or a requirement to switch off at night.
- Remedy: ask the building authority before ordering, in writing, with a photo of the façade. What belongs in a signage application is covered in the chapter on law and permits.
Mistake 12: the technology bought before the goal was clear.
- Symptom: a device sits in the storeroom, or it hangs and runs, but nobody can say what for.
- Cause: a good offer, a trade fair visit, a device that happened to be cheap.
- Remedy: write one sentence first: this screen is meant to achieve one specific thing, so that one specific thing happens. Then come the location, the content and the responsibility. The device comes last.
The quick diagnosis
When an installation plays up, it helps not to start unscrewing the device but first to name what you see. The table below is the order we follow when we arrive at a site.
| What you see | Likely cause | First move |
|---|---|---|
| milky, grey picture in daylight | too little brightness, reflection of the façade opposite | check brightness, turn or tilt the device |
| black picture, player is running | screen on standby or wrong input | check the schedule and CEC, swap the HDMI cable |
| videos stutter | bitrate too high for the player | re-export the video, lower the bitrate |
| content out of date | nobody is responsible | set a name, a date and an expiry date |
| type illegible | page designed at a desk | check from the real distance, shorten the text |
| device shuts down in summer | operating temperature exceeded | ventilation, sun protection, a suitable device |
Note what you checked and in what order. Next time you will be through in ten minutes.
How to recognise a good installation
Walk round your own installation once with this list, ideally in pairs and at a time when the place is busy. Whatever you cannot tick off is your next task.
- You can read the core message from the real viewing distance, without squinting and without stepping closer.
- The picture is rich even in sunshine, not grey, and the façade opposite is not reflected in the middle of it.
- The centre of the picture is at eye level, the device sits straight, the joint to the wall is clean.
- The loop matches the dwell time, and the most important message appears twice.
- No cable is visible, no power strip lies among the displayed goods.
- The installation runs silent, or the sound is wanted here and cleared legally.
- One person with a name maintains the content, and every campaign carries an expiry date.
- Every device reports on itself, and an outage is known on the same day.
- The permit exists in writing, including conditions on brightness and night-time operation.
- You can say in one sentence what this screen is for, and your staff can too.
Ten ticks, and not one of them expensive. Most of them cost a decision and twenty minutes.
Key pointMost faults are not faults at all, but decisions made six months earlier.