We've had a Shark IC160UKT vacuum cleaner for about 4 years. The motor has started making a high-pitched whistling noise but otherwise the Shark has been cleaning well. Yesterday it began cutting out after a few minutes' use, giving the "blocked" warning (boost and carpet lights flash). So I washed the sponge and half-cylindrical filters (having previously tried blow-cleaning them), and blew round the motor housing in case there was dust in there, because the area around the sponge filter by the motor air-intake very quickly gets a coating of dust on it. I've also cleared out the inevitable hairball that builds up in the flexible hose, and cleared any hairs from the rotating brush.
Now that the filters are dry, I've tried it, and it errors immediately, without even starting to spin the fan. The very first time it turned the brush very slowly for a few seconds, but it hasn't even done that since then. I've tried it in "lift away" mode - without the connection to the base that has the brush - no difference.
The battery is fully charged: it is displaying 3 LED segments. If I put the battery back on charge, only the third segment flashes, implying that it is almost fully charged.
Any suggestions? Shark's FAQs don't go into any more detail than "if the boost and carpet lights flash, clean the filters and hose - check for blockages".