Upper rack dishes are not getting clean while lower rack is fine.

Safety first: Turn off power before removing spray arms if accessing from below.

• Clean upper spray arm: Remove the upper spray arm and clear all jets with water and a small brush.
• Check feed tube connection: Ensure the upper rack feed tube properly engages the rear manifold when the rack is pushed in.
• Inspect mounting: Verify the upper spray arm spins freely and is not sagging or rubbing on dishes.
• Address circulation issues: If both arms are weak, inspect and clean the circulation pump inlet and filters.