Goldstar FF Fridge/Freezer GR3823CRI Defrost Timer?

Hi,

I need a defrost timer for this machine. Can anyone point me in the right
direction or even give me a part number. I think it is made by LG.

The problem with this machine is that ice forms in the ducts formed in the
polystyrene cover situated at the bottom of the evaporator. The
evaporator itself does not ice over.

I thought the outlet from the run-off chanel might be blocked but the ice
melted and ran through the tube ok.

When I turn the defrost timer manually and it clicks – all the machine
continues to run. So I am assuming this is faulty and is not having a
`defrost moment`.

Thanks

Laurence