I have been using my HP Deskjet 5150 printer for approx. 10 years now.
It is still a dependable printer. Never get paper jams. Never needed any repairs.
After years of use, you may be puzzled after you replace a printer cartridge and shut the top cover that you get an "Open Cover" message. This is easily fixed.
After you open & shut the cover several times, resist the urge to get frustrated.
The cover latches easily at the bottom edges leading you to think it is properly closed, but it is not.
If you look at the right hand edge, you will see the cover is not quite flush with the casing.
You just need to move the flexible cover a tiny bit as you close it and press on the right hand side until you hear a click.
Open the cover, notice that on the right hand edge of the cover there is a small triangle.
On the case there is a hole that contains a black cover switch.
When the triangle lines up properly and enters the hole, you will hear a click.
Then the cover will be flush with the casing and your printer will be OK again.
Below is a link to a good explanation by "techonarock" on Sep 16, 2008.