Daughter purchase a radio controlled alarm clock from Lidl a couple of
weeks back but although the clock and alarm function well, the
advertised motion sensing alarm cancelling did not work.

She returned it to the shop and a manager opened another box, waited
for sync (2 AA batteries supplied in clock), set alarm and tried to
cancel without pressing the button but no success with that one
either

Daughter brought this second clock to me at the weekend and I
dismantled it and found the usual RF clock module with black blob chip
but with a second small pcb with another blob and wires to battery,
snooze switch, a copper foil strip on the case front and a couple of
blue LEDs (which were supposed to come on for 3 seconds on pressing
the button - another non-working function).

Examined surface mount component soldering under eyeglass and checked
battery voltage. There were 3 wires to the four tags on the battery
compartment. Tracing them revealed that the clock module worked off
one cell only but the LED/snooze/motion sensor pcb used the full 3
volts - which was absent.

Opened battery container and probed both batteries - ok. Then noticed
the second piece of thin transparent plastic that had to be pulled out
from between the other cell positive and contact.

Assembly was the reverse....