In message , Harry
Bloomfield writes
AA Pro-cells are one example which cause the problem along with the
cells actually included with the unit at purchase. I actually took one
back to Maplin, thinking the units PCB had become intermitant. Maplins
tried some new cells with the same result and replaced it with a new item.

Duracell, known problem with them and poorly designed battery
compartments, the 'pip' on the top makes intermittent or no contact
because it's either too wide or not tall enough (sometimes both with
some really bad battery compartments).

Other makes also suffer but I can't remember which ones I have had
problems with off the top of my head.
--
Clint Sharp