The dishes aren't clean
You might think that if your dishes are coming out of the dishwasher with food residue, your dishwasher is done for. That's not always the case, though. "If your dishwasher isn't cleaning well, the first thing you should do is check to see if there are any food particles in the filter, which is located in a cylinder at the bottom of the machine," advises Albert Lee, founder of Home Living Lab. If you don't see any, then your next step is to give your dishwasher a thorough cleaning, says Audrey Monell, president of Forrest Anderson Plumbing and Air Conditioning in Glendale, Arizona. That includes pulling out the filter and rinsing it in hot, soapy water and cleaning the spray-arm, which can get clogged as well.
If you're still not getting clean dishes, it still it doesn't necessarily mean your dishwasher is dying. Hard water or caked-on food could be the culprit. Of course, if nothing you do is helping, then that may be a sign your dishwasher is dying and it's time to seriously consider shopping for a replacement unit. Whether you keep your old model or get a new one, make sure to avoid these 21 mistakes that shorten the life of your dishwasher.
12 Signs Your Dishwasher Is Dying, Source:https://www.rd.com/list/signs-your-dishwasher-is-dying/