You mean the screen or internally? The inlet has a removable screen that can be pulled out and replaced. The city water inlet has a check valve inside with a spring/valve mechanism and these can get plugged up with sediment. With the screen off, you could try flushing the valve. Don't poke anything in there that can damage the check valve. If the check valve cannot be cleaned, there are two options. One - replace the entire city water inlet which will also involve a little caulking - not a big deal really. Two - undo the water line from the inside and punch out the guts of the inlet, clean and install a new check valve on the interior side of the inlet. Make sure to get all the pieces out. Interior side of the inlet will have standard 1/2" threads and check valves are available at any plumbing or RV parts supplier.
I removed the guts from our city water inlet and enlarged the opening to improve flow and then installed a good quality commercial grade check valve on the interior side. Our inlet was easily accessible behind the kitchen drawers and had a 1/2" swivel fitting that made this mod easy.
