Re: mobicool A40 portable cooler box
We used to do this all the time many years ago with the Morphy Richards absorption fridges, turn it upside down, give all of the pipework a good knocking and turn it back upright.
Worked at least 50{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} of the time. 8)
I was told it was due to the refrigerant crystallizing and blocking the smaller capillaries, inverting it sometimes flushes the blockage away, (at least temporarily). 😉