you already open the boxes(jacks). Very good.
The jacks seem okay.
First make sure your telephone is working at other jacks.
e.g., Check it at your neighbor's jack.
If not working, your telephone is no good.
But try a new cord, if you can change it
or cut the plug to connect the wires directly to the jack.
If the phone is working on other jack, then the jack is the problem.
I would first shake the plug a little.
Then check the copper wires connection points at the jack where
your plug it in the jack to see whether they are bended.
If it is, then get a new jack reconnect the 4 wires.
Actually red and green should be enough.
The jacks seem okay.
First make sure your telephone is working at other jacks.
e.g., Check it at your neighbor's jack.
If not working, your telephone is no good.
But try a new cord, if you can change it
or cut the plug to connect the wires directly to the jack.
If the phone is working on other jack, then the jack is the problem.
I would first shake the plug a little.
Then check the copper wires connection points at the jack where
your plug it in the jack to see whether they are bended.
If it is, then get a new jack reconnect the 4 wires.
Actually red and green should be enough.