UK Appliance Repair Questions? Ask a Technician for Answers ASAP
If it sat unplugged, it would have defrosted and corrected any air flow issue from frost built up. I suspect that is why it is now cooling. If that is the case, it will frost up again in about 5-7 days, so watch the temperatures. There are several components in the defrost circuit but the most likely to fail is the thermal fuse in the freezer that is mounted by the evaporator coil. If you can remove the rear cover from the freezer (inside) and post a picture, I can mark it for you.