Email one, from the client, month fourteen
"One panel on the wall has gone black. The supplier says the power board is on backorder, fifteen days plus freight. Can you help?"Not our wall. But the problem was familiar enough to write down.
Email two, our reply
"Fifteen days is not unreasonable for a two-generation-old board. It is also three weeks of a black rectangle in a control room, which is a different kind of cost. Two questions: does anyone stock the exact revision, and is there a compatible board in a newer revision that fits the same connector? Sometimes there is. Often nobody has checked."
Email three, what they did next
Found a board from a decommissioned wall in another building, swapped it in, ran for eleven days on borrowed parts.That worked because facilities kept the old wall instead of scrapping it. Most teams do not, because a store room looks like waste on a balance sheet until it is the only thing keeping a screen alive.
The rule we now write into handover
Two percent of installed panel count as spares for any wall over twelve panels, minimum two units. For a twenty-four panel wall: one spare panel, one power board, one T-con board, one set of signal cables.Two to four percent of wall value. Less than one emergency call-out with air freight.
What else goes in the box
A labelled copy of the factory menu settings. A replacement board often needs the original colour calibration written back, and without the numbers nobody can do it.Two cables of the length actually used. A spare IR receiver strip if the wall has touch. Serial numbers written on the lid.
And the contract line nobody asks for
A written response time, and a written part availability period of five to seven years from delivery. Whether the spare ships from stock or from the factory.A supplier who cannot answer both is not planning to support the wall at year four. They are planning to sell you a new one.