Even a remote situation like that has "regular" traffic, although at 6 month intervals. You're not the only ship that comes through on a long circular route, but possibly the only one for the next 6 months. If you break down in the uninhabited system that you and the other ship(s) on the circuit need to traverse, you're going to have to sit and live off your supplies for 6 months until that next ship on the route or some other random traveler passes through, but you're not dead.
The planet you're expected to arrive in will know something is amiss when you don't show up 2-5 days after you're due, and will pass word along if they have HPG capability. If they don't, then the other ship on your run will either find out when they show up in the uninhabited system where you broke down and receive your radio hail, or else when they arrive at the planet you were destined for, find out that you're missing, and then either head back a jump to search for you or carry word on to their next stop, which DOES have an HPG transmitter.
Basically, a jumpship, the dropship(s) it's hauling, and all of their crews and cargos are far too valuable NOT to keep track of, or spend an incredible amount of effort to recover. If it doesn't show up, somebody is very certainly going to start searching. If they can't find you after backtracking along your route, hunting for debris, messages, or other signs of a problem, and then carefully considering where else you could have gone, then they'll eventually write it off as another mysterious misjump or possible hijacking incident. You're in little danger of being permanently abandoned along a known travel route.