Old tomtom xl model n14644 - getting updated gps fix

First, I put this as a comment rather than a question so apologies. I can no longer buy updates including gps fixes , and so gradually the 5 bars display has come down to 2 bars and I am now getting some oddities on the display like the arrow not staying on the road display . Is there another way of getting gps fixes in particular.? Thanks in anticipation