How do I know if my campervan fridge is beyond repair?

I have a 1998 camper with the original Electrolux 3 way fridge. Before the winter the fridge seemed to be working fine. Now it will not cool on either 230v or gas. I can get the gas to light and stay on OK tho the flame looks a bit weak. Any ideas? Do you think the fridge is kaput or are repairs possible. The van was sitting outdoors with a good cover over it through all the very cold weather in Dec/Jan. Might that have affected the fridge working?