Replenish internal sensors when the computers are offline
The internal sensors do draw cards from the skill deck as needed to ensure that there are always 3 cards available when it and the computers are online. Once the computers go offline the cards that are currently in the internal sensors remain but there is no longer any skills for it to draw.

The rules are pretty bad about explaining how all the systems work but in this case the card itself talks about drawing cards and the only place you draw cards from is the skill deck which can't be done when there is no skill deck do to the computer being offline.

The reason why you don't see any other examples of one system directly impacting another is because the other systems are not as closely related as these two are in dealing with the same end result (skill card) in a slightly different manner.