This can be temporary if caused by a passing thunderstorm or permanent if your dish installation is faulty or obstructed. Let's deal with each of these in turn, starting with the temporary problem of Rain Fade.
Rain fade is loss of signal caused by rain getting between your dish and the satellite in space or between the satellite and the transmitting dish at the DStv broadcast company in Randburg. There isn't much you can do about this except to make sure your dish is perfectly adjusted by an accredited installer with a signal strength meter or fit a larger dish which will provide a stronger signal and overcome the signal loss of smaller storms.
Obstruction is usually caused by trees or overhanging roofs or balconies. The solution here is to prune the tree or move the dish to a better location where it has an unobstructed line of sight to the satellite. Special dish brackets are available which allow your dish to be mounted on the wrong (West) side of your house and face East over your roof and above the trees.
People often ask how is it that the dish worked since installation and only now became obstructed by a tree? Besides the obvious answer that trees grow new branches, another reason is the change of seasons. The dish might have been installed in Winter when there were few leaves on the obstructing branch and then in Summer new leaves grew and reduced the signal reaching the dish.
A faulty satellite dish installation has many possibilities:
The LNB (Low Noise Block) could be faulty and this is common after a thunderstorm because LNBs are sensitive electronic items. The LNB is the "eye" on the end of the metal arm facing the dish.
The LNB skew angle could be incorrect resulting in a high Bit Error Rate (BER) and low signal quality. This is the result of non-accredited installers using a Satellite Finder or cheap signal strength meter which does not have the ability to measure BER.
The dish itself could be misaligned due to being bumped or not securely mounted, and if not installed professionally was maybe never properly aligned in the first place.
Water could have gotten into the cable. When this happens it is the result of old cable which has cracked in the sun or shoddy workmanship where the F-connector on the cable has not been properly waterproofed at the LNB.
Water could have gotten into the LNB which can happen after many years when the front plastic cover cracks in the sun.
Inline cable joints may be faulty, especially where they are outdoors and exposed to moisture. Ideally a cable should have no joints and if a joint is absolutely necessary it should be made indoors not outdoors.
F-Connectors could have come loose from the cable. This happens when a decoder has been connected and disconnected many times or when a domestic servant has accidentally pulled a cable out of it's connector when cleaning behind a TV cabinet.
You can clear some DStv error codes (E16, E17, E18, E19, E30, E32, E107) yourself by using the following self service procedure.
Click on the button showing your error code number to read the reasons for the error and possible solutions.