DIAGNOSIS This is almost always a clogged or partially blocked exit needle—the one that pierces the top of the K-cup. When it’s clogged, not enough hot water gets into the pod to brew properly.
FIX You need to clean that top needle. 1) Unplug and cool the machine. 2) Lift the handle to open the pod holder. You’ll see a silver hood with a needle in the center. 3) Use a small paperclip or the tool that came with the machine to gently scrape around the base of that needle. You’ll often pull out a plug of old coffee grounds and paper filter. 4) Wipe it clean with a damp cloth. Run a few water-only cycles to rinse.
IF THAT DIDN'T WORK If it’s still weak, check that you’re using the right brew size for your mug. The ‘Strong’ setting only works on the 6oz, 8oz, and 10oz sizes. Using a 12oz cup on ‘Strong’ will still dilute it too much.
HEADS UP Do this top-needle cleaning every 2-3 months, or whenever you change the water filter. It’s the most overlooked maintenance step.