I’ve tried adjusting the mech, new cable, but the shifter seems knackered to me, holding tension on the cable by hand it goes up all the clicks fine, sounds crisp and all consistent, but will only come down 3 or 4 gears, then stops, can’t hear it clicking, and even to get that far have to use every bit of the lever travel.

Any ideas? Don’t really want to buy a new one, when casette wears out I’m likely to go 10 or 11 spd

New cable and outer?

Yep. No clicks coming down even when cable not attached to mech and holding cable under tension by hand.

I’ve had one (also a deore) do something a bit similar; you could twiddle the lever but nothing happened. I think it had just gunged up; I liberally drowned it in GT85 and it seems to have been fine since, touch wood…

If you disconnect the cable from the mech does it pull back easily by hand at the shifter end?

Often caused by a little pawl getting gummed up inside, a drop of GT85 on it’s pivot, and a little working back and forth uusually sorts it out, but requires removal of the covers to gain access without drowning everything else too.

Are the cables caught in the bike stand clamp? This has never been happened to me obviously.

Mech is fine, brand new cable, brand new outer, nothing snagging, all goes ‘up’ fine but won’t come back down, the problem is definitely in the shifter.

So, a million dingbat points to me, I replaced the inner wire, outer, changed routing, had shifter apart several times, tested it, tried it, worked fine with shifter away from other handlebar furniture. Turns out the downshift trigger was touching the front brake reservoir *just before it reached full travel, couldn’t tell without looking very closely, so swapped brake and dropper lever over, job done!