Comment by janxgeist

We had a similiar problem with a label printer.

On some days, exclusively in the morning hours, the printer would fail to detect the start of a new label, printing over several labels.

After connecting remotely and checking the usual (queue, network connection, drivers etc), I asked my colleague to call me, as soon as it happened again.

When I went there, I saw that a ray of sunlight hit the printer. The windows had shutters, but there was a gap.

Label printers detect the gap between labels using a laser. And for some reason, the printer's case had a clear window at the top.

I printed an empty label and stuck it on the little window.