My maytag quiet series 300 leaves gritty food all over the dishes on both racks and inside the glasses and cups. I have changed detergents, used both baskets of rinse aid plus the liquid in the dispenser. It does better when we use a lot of rinse aid, but I hate putting so many chemicals on my dishes. We have a water softener for the whole house.

https://www.maytag.com/content/dam/global/documents/201508/owners-manual-W10783959-RevA.pdf
Click on this link for a PDF manual from Maytag.
page 10

You did not list the model of the machine. But it appears to me that the disposal in the unit might be in need of work. There are teeth in the machine that grind food.

If your dishes or glassware appear filmy or spotted following a complete wash cycle, adjusting the amount or type of detergent you’re using and adjusting your hot water heater’s water temperature may solve the problem. But before you do either of these, put a rinse additive (such as Jet-Dry) in the rinse dispenser to improve the sheeting action of the water.

Next, you’ll have to determine whether the film is removable or permanently etched. To do this, soak a glass in undiluted white vinegar for about 15 minutes. Or, wash the glass with warm water and concentrated dishwasher detergent or a high-phosphate detergent (such as Glass Magic).

If the film comes off, it is probably caused by hard water minerals, improper amounts of detergent, or unsuitable water temperature.

Permanent etching is often caused by a combination of soft water and excessive heat or detergent. If glassware is permanently etched, there isn’t anything you can do to make it clear again. But you can avoid future etching by taking these steps:

1) Be sure hot water entering the dishwasher is no hotter than 140 degrees F. Don’t use extra-hot settings such as “Power Scrub,” and use the “Energy Saver” dry cycle.

2) Adjust the detergent amount.

3) Don’t pre-rinse your dishes before loading them in the dishwasher. Food particles on the dishes actually help the detergent and drying agents clean better.

A common cause of poor washing results is improper loading—dishes that block or impede the spray arm(s) or prevent the soap dispenser from opening. On the other hand, if your dishwasher has chronic problems with good washing, the problem may not be your dishwasher. A good first step is vary the amount of dishwasher detergent you're using and try switching brands.

Other possibilities: Your home’s water pressure may be too low, your water may be too hard, or the water temperature may not be hot enough.

In order for your dishwasher to fill to the appropriate level, water pressure should be from 20–120 pounds per square inch. If you suspect that your water pressure may be low, turn off all faucets or other users of water (such as washing machines and sprinklers) and then put a half-gallon jug under the kitchen faucet. Turn on the hot water full-blast. If the jug doesn’t fill within 14 seconds, your water pressure may be too low for proper dishwasher operation. Call your city water utility to discuss your options, or avoid drawing water elsewhere in the house or yard during dishwasher cycles.

The right amount of detergent to use depends on how large your load of dishes is and how hard your water is. Hardness is measured in grains of minerals—the more grains per gallon you have, the more detergent you’ll need. If your water has 12 grains or more of hardness, fill both dishwasher soap cups completely with detergent. If that doesn’t work, consider installing a water softener. (For more information, see the article Water Softener Systems.

To check water temperature, hold a meat thermometer under the hot water faucet for two minutes; if it doesn’t register a minimum of 140 degrees F., turn up the temperature dial on your hot water heater. (However, if you have a newer dishwasher that heats the water internally, it isn’t necessary to turn up your hot water heater.)

If your dishwasher has worked fine in the past but suddenly your dishes aren’t clean after the dishwasher completes all cycles, listen to the spray arm(s) spinning inside during the wash cycle. If spinning poorly, wait for the machine to cool down, remove the spray arm(s) by unscrewing the hubcap(s), lifting the arm(s) off, and then cleaning out the spray holes in the spray arm(s) with a stiff piece of wire.

Try the cascade new soap they have been changing the ingredents due to state requirments for the water treatment. also make sure spray arms and jet are free from food particles,also clean soap dispencer,If you want run CLR through dish washer no dishes to clean machine.Thanks

Don't be afraid now, but , what I'n going to tell you works VERY often. Pour two cups of bleach into the washer and let it run a potscrubber cycle. They do this all the time at restaraunts, yes really! Let me know how this turns out. P.S. leave the machine empty when you run it. Thanks, Dana

Had similar problem with our Maytag dishwasher--we removed all spray and screen components to the inner case, cleaned the intake screen below the lower spray arm, repaired a split upper spray arm, and inspected everything for cracks or other distortion. All of this helped some, but finally improved things by changing from liquid detergent to a "packet" type. Our water is somewhat hard and builds deposits on the screen at the bottom. Run a no-dish cycle with a cup of white vinegar in the bottom.

A water softner will not make the dishes any cleaner, it just makes it so they don't have water spots on them.
If the dishes are dirty, it is most likely that the nozzles (holes) in arms may be plugged.
Also check to make sure you are getting plenty of water to dishwasher. Make sure all water valves are full turned open.

If the control panel does not work all the time, it is very likely you have either a shorted wire, or a fualty main board which is very common in newer machines.

Check for foreign objects like glass or plastic at the grinder blades. Some dis assembly will be required. See appliancepartspros.com for diagram.

Very common problem is soap build up in these machines. Try putting it into a wash cycle with no dishes, and no soap. Let it wash for about 5 minutes, and then open the door. If you see alot of soap suds, then soap build up is the problem. Try doing a couple loads with no soap, and no dishes, and throw a cup of vinegar into the machine halfway through the wash. Repeat as necessary. This should solve your problem.

My model is simillar Cheri's. Every couple years I have to remove the plastic spray bars. They are held on by a simple torque screw. Once removed you will see debris plugging many of the holes. I have found this on all 4 of my spray bars. This debris prevents the right amount of water in the wash and rinse cycles. The upper spray bars seem to be the worse. This explains the trouble most folks have with glasses in the upper rack. Also check the docking station. You will fiind it along the back wall of your unit. The plastic tubes on the backside of each rack will slide into a hole in the docking station. After a few years the rubber seal in the docking station will be worn away. Once this happens, it prevents the correct water pressure to the upper rack. The replacement part snaps into place and cost about $25.