Put it on the smallest ring and remove the slack.

If I understand you correctly you're setting your shift lever and chain to the middle chainring and then setting your cable tension. Try this. Screw the cable adjuster screw on the shift lever all the way in and then unscrew out around 3 full turns. Shift the lever to the lowest gear position (i.e. for the smallest chainring), Put your chain on the smallest chainring, pull the cable fairly tight with some pliers as it's a little difficult to pull the short length of cable with your bare hands, clamp the cable and it should work. Use the cable adjuster on the shift lever for fine tuning. There is also the possibility that you'll need to make some other adjustments which can be addressed in some " front triple derailleur installation/setup" videos. Park tools makes a good one. https://www.parktool.com/blog/repair-help/ There are many other good videos on this and some are even made by BikeForums members. You mentioned that watching some videos didn't help but keep looking until you find one that works for you.

Now all front derailleurs, lever pulls cable , cable pulls from low to high , It's return spring pulls back..

Logically, it will settle in, where the return spring pulls it, * attach the cable at that point.. To pull it to the other chainrings

* L stroke limit screw keeps ir from going too far in. .... H stroke limit screw keeps it from going to far outboard ..






A follow up, is ... When are you shifting? mashing or spinning lightly?




....

Follow this procedure from the beginnning, without skipping any steps: https://www.parktool.com/blog/repair...eur-adjustment

The elephant in this thread is "the gear shifter has been altered and looks right -doesn’t make a difference .

How is this determined? How do you know if it does make a difference? Did it work before playing with the cable?

One should be able to move the ft der with your hands while rotating the cranks and have it shift. Granted this can be hard to do if sharp edges bother you fingers or if your hands are not strong. No cable aspect at all to not have that influence how the der's travel and positioning work. Andy

I agree -- this bike has twist shifters, or Shimano's version of GripShift. I've never seen an inexpensive grip shifter go through "alterations" and come out better, or ok. Those things just break.

If you disconnect the front derailleur cable, and the chain shifts to the small chain ring, I'd suspect you need a new shifter.

Or the cable was too tight to begin with. I wonder if the "shifter alterations" refers to the der and not the Revo shift control. Andy

Yes, I think that there's very good diagnostic specified above. Disconnect the cable and see if the derailleur shifts the change to the small chainwheel. If not, then the problem (at least all of the problem) is not with the shifter.

Can the OP state what was meant by " the gear shifter has been altered and looks right -doesn’t make a difference

What was altered? What doesn't make a difference?

You are pedaling or turning the cranks forward when you try to shift the gears...... correct?