Home Automation - Garage door opener safety sensor

I had to replace the receiver unit on the safety sensor. Wire on old one cut/broke at receiving unit, not enough wire to splice.
Got ahold of compete new beam units. Only replaced the receiver as the new beam units look exactly like the present one.
Spliced the receiver in, and turned on the opener. The sending unit has a small green light glowing, the receiver has a small red one. But, I do not see any beam being emitted from the sender toward the receiver, nor does the motor respond to the remote or wall switch.
I have no instruction booklet for this opener. It is an older style Craftsman.
Any thoughts or suggestions?
Thanks in advance
Skysoldier:confused:

You won't see any beam, it's infared. Do the lights blink on the opener when you push the wall button. Will the door move when the wall button is pushed and held down?

Unplug the opener for 10 min or so then plug it back in and see what happens.

It may need to be reprogrammed for the remotes to work, but get it working with the wall button first.

What is the model number?

The unplug/wait/replug worked in that the motor works, and engages the door.
However, it is now sensing something blocking the door path and does not want to close the door. It stops, retracts the door and the main lights blink
There is no blockage, and nothing in the track. I can close the and raise door manually and smoothly with no problem.
Skysoldier

what about the holding the button down thing? does it close then? How many blinks of the main lights? Does your unit have the LED's on the motor unit itself?

This is getting to be funny, in a sense.
It will now close fully, then opens right back up. It works from the wall switch, and the remote. But, it will not stay closed.
I held the button down the entire closing process, last time. The door closed, but as soon as I released the button, the door retracted.
It now closes completely once the button is pushed. It will do so without the button being pressed more than once or held. However, as stated, it opens right back up.
I do not believe it has LED's. It is a discontinued model with several numbers and what looks like s or RS or RT at the end of the model number. It is a 1/2 hp model, and is at least five years old. It was the one prior to the current model, I believe.
Also, to answer one question, I thonk the lights would blink three times, but I am not certain.
Skysoldier

Sounds like the down limit needs adjustment now. Should be a knob or shaft on the side or back to adjust down limit (not down force).

You may want to take the cover off and make sure all cards and plugs are fully seated. Sometimes when symptoms change like that, that can be the cause, or just the logic circuits on the boards need to be reset.

Craftsman is made by Chamberlain...I don't have any sort of cross reference. I think a couple of the experts on here do, but I haven't seen any replies this weekend by them yet.

Adjusted travel which was becoming an exercise in futility. Did not realize the settings were as fine as they are, and kept overadjusting both directions.
Located the limiters, adjusted that slightly, and now have an properly functioning garage door opener.
Guess you can teach an old dog new tricks.
Thanks to all for their input. Greatly appreciated.
Skysoldier

I should have stated "Thanks to Gun guy" for providing the assistance and information I needed.
Sua Sponte
Skysoldier
RLTW

Glad to help...

If you were just a leg it might have been different...lol

Ex-"haze grey and underway" here