Other comments mentioned replacing a diode -- I know what a diode is conceptually, but I have no idea how does it look in the appliance, where would I buy a new one or how to replace it.
Being as clueless as I am, my only option is to call a proffessional. Sometimes it is worth it -- I had a fan on my MacBook replaced for ~700 SEK which is a fraction of the price, but sometimes it's not. Our 1 y/o kitchen oven bought from IKEA started malfunctioning, so we called one of the repair centers they subcontract repairs to. They sent us an invoice by accident even though the oven was covered by a warranty and I couldn't believe my eyes. The cost of the new oven was IIRC ~5000 SEK (~500 USD), but the repair was over 4500 SEK, 3k for the replacement part (!?!) and 1500 for the repairman to come and do their job. I didn't know the cost upfront and I guess they wouldn't have told me an estimate without looking at the oven, at which point I would have to pay the labour cost anyway..
So sadly, given the cost, I would have probably opted for just buying a new item if the faulty one is out of warranty..