The indexing shifter (lever for down, click for up type) doesn't seem to have enough range to cover the entire 7 gears. Limiting screws are all the way out. If I adjust the cable I can get 4 lower gears or 4 higher gears or anywhere in between, but only 4 gears.
The shifter display will only go down to 4th. It's like there just isn't enough range in the shifter to cover all 7. The dérailleur can move the full range.
The bike was bought almost new with very minimal use and as far as I know the gear set is original.