Why does my dehumidifier stop collecting water? ?

Is it one of these?

https://www.amazon.co.uk/Aqua-Dri-Portable-Dehumidifier-Moisture/dp/B0015M2492

https://www.amazon.co.uk/Aqua-Dri-Portable-Dehumidifier-Moisture/dp/B002T3VPCS

Assuming the power supply is OK (if the fan is running, that would seem to be the case) there is not much to go wrong, other than probably a failed Peltier element.

Best bet seems to be to simply buy a new one - unless yours is less than 2 years old, in which case the 2 year warranty may be useful.

XXX
November 2016