IceRoadman,
It would be really sweet to have some sort of a signal generator that you could use on the bench to simulate the output of the LNBF and inject it into the receiver or to simulate a satellite transmission and direct it into the feedhorn of the LNBF, but alas, there isn't anything available for a general consumer of satellite equipment that will accomplish this within our budgets. Nothing off the shelf anyway.
You could probably improvise and develop some sort of signal generator to at least simulate the L band frequency carrier to inject into the receiver (to simulate the LNBF), but you would have to have the equipment at hand. Most people don't have this sort of equipment and wouldn't ordinarily go out and purchase it due to the cost vs use ratio.
The least expensive method would be to have enough redundant components (LNBFs and receivers) and an actual real-world dish so that you can utilize an actual satellite signal and troubleshoot through a trial and error and swap and test method.
If you are certain that you have your receiver parameters set appropriately to match the LNBF type (i.e. the L.O. / local oscillator or LNB Frequency) and polarity and any switching concerns (not for external switches, but for any switching that might be processed internal to the LNB itself) then you should be able to extrapolate the health of the LNBF or receiver from what you detect on the signal level meter of the receiver.
As Lak stated, you should at least detect some indication on the signal level meter, even if you don't see anything on the signal quality meter.
The signal level meter not only registers a valid signal from a satellite, but it will also display oscillator or amplifier noise from the LNBF if the LNBF is "alive". Every amplifier (LNBF) generates some level of background noise so that even if you seal it up in a lead box, you should detect some signal from it if it is not totally dead.
If you disconnect the cable from the back of the receiver and look at the signal level meter, it should show virtually zero signal indication. Connect the LNBF to the receiver and the signal should "POP UP" to some weak level regardless if it is attached to a dish and aimed at a sat or laying on the bench in the house.
If the receiver and LNBF are working and it is the dish alignment that you are questioning, then if you have the LNBF attached to a dish, and especially to a motorized dish, you should see the signal level increase and decrease and increase again as you drive the dish (or manually pan the dish) from east to west and back. The signal level meter may not switch from an invalid to a valid signal (like changing from red to green or whatever color scheme your receiver uses) but it should increase and decrease as your dish comes near to a satellite and then passes it by. As long as your dish is somewhat reasonably aimed, this should work. If your dish is aimed so far off (like in the opposite direction from where the satellites are) then don't count on this. Truly, some people have aimed their dish off a north facing balcony towards the north pole in the northern hemisphere and couldn't understand why they weren't finding a satellite signal! It does happen.
The signal level meter will act somewhat like the beeper on a metal detector in this regard.
If you show absolutely NO signal level indication on your signal meter, then either your LNBF is dead, a cable or switch is open or dead or the receiver tuner is dead, or the receiver's setup parameter(s) are incorrect for the specific LNBF that you are using.
Therefore, if you know what signs to look for, you don't really need any laboratory test equipment to verify the health of your components. You can use logic and deduce from the results what the likely problems are, if any.
Hope this information gives you something to chew on and play with. Good luck.
RADAR