Pentair Intellichlor ic40 all green but not producing

[concort]

So my chlorinator is not producing chlorine. Its been sort of on and off now since the start of this summer season here in the North East (PA). It was producing chlorine then it wasnt then it was.... Heres the current situation:

Pool and chlorinator are 9 years old. I cleaned the intellichlor at the beginning of this season with acid/water. There was no scaling in it btw but cleaned it anyway due to low chlorine readings and red lights flashing on the unit. Later is started to work again but its always intermittently. Fast forward two months now the Good and Low lights lights are flash red on and off AND the Flow red light as been on. So i finally replaced the flow sensor. That now made everything change back to green. All lights green and it SEEMS all systems go. My pool is now registering around 4000 for salt level... so its a little more than i need. Pool is about 19000 gallons. Water temps are around low 80s. So no issue with temp. The unit is STILL not producing chlorine. When i pour shock/chlorine into the pool then test after a bit then i register chlorine showing... so this unit is def not producing atm. Incidentally the Cell light is never light and when i run the diagnostic sequence on it it shows like 60% so still seems to be life left in it according to the diagnosis. Im stumped. Any ideas??

[Teapot1]

A 9 year old cell is likely at or passed its life span. Test the output current to the cell to confirm the power supply is still working and then its pretty much a worn out cell.

[concort]

There is def power... All the lights are green on it but this thing just wont produce chlorine. I would have it set at 100% for up to two week and still my test strips show no chlorine. In the passed i would run it at 100% for 2 or 3 days and it would show loads of chlorine. Doesnt make sense. If the cell is bad wouldnt the flow light or cell light be RED?

[Teapot1]

Green lights should mean all is well but it doesnt mean the power supply is producing sufficient current at the cell, hence why the point of the cell connections needs testing.
Dip strips are not accurate or reliable, have you tested those with a drop of bleach in a bucket of water? A 9 year old cell is past its prime usually and can stop producing.

[concort]

Yes i have tested those strips in every way and those strips have been very reliable to me at least for the passed 9 years. Yeah im guessing this thing might just be kaput....Still extremely odd that all lights are on when youd think logically it would show a RED light on the CELL if things were amiss in the cell in anyway. <insert sigh and headshake>