Defrosted Freezer and now not working.

Ever since I defrosted the upright freezer of mine it refuses to pull below -15C. Compressor runs constantly. It`s a Hoover Nextra on R600. Any ideas guys? I work on transport reefers so not up on domestic. If it was a leak I would have thought it would have quit altogether by now.

Hi
Most likely you have lost some charge. Most R600a units have their process connectors for vac and charging simply crimped off and not brazed sealed and consequently the one on the drier often has a slow weep . I've re charged and sealed up several R 600a units for friends without problems. Look under the drier , you can often see a small oil stain on the metal work in the dust as a clue .

Maybe check door seal as first basic thing.
Should take a little effort to open if sealing, sometimes clear ice you can't see, or obstruction like a basket or shelf.
Run fingers over door seal, also might notice fluffy ice inside where seal not sealing.