Stihl MSA 160 C problem

[PhilZ]

I'm new to the forum but not this saw.  
       I have been using this saw for over 6 yrs with no problems, last week it suddenly stopped. Battery showed 3 red leds on battery, I've never seen red before. 
    Removed battery checked test button and it showed 3 green. Charged battery, cleaned battery compartment, replaced battery, nothing. Removed bar and chain, nothing binding motor.
I would like to find a source to diagnose the lights meaning,  and the problem with the saw. Or find information on how to open to the motor & guts. I did find one source that directed me to take it to an authorized repair. The one near me is forced closed from fear of the COVID by our Ky governor.
  

[Air Lad]

Can you get your hands on a second battery
That makes it easy to find problem between bat or motor
Is it brushless ? If not check brushes
They can be easily replaced if so. As a tradie I have had numerous issues with triggers also.
Most can easily be taken apart. Just not a bull at a gate
Steady as she goes Mate

[Nathan4104]

Sorry to hear of your issue, I have a 140c that's brand new.  What i've used it so far has fit the bill and it's been great. 
Here's a pic from the manual about the lights..... asssuming things are the same, looks like your battery may be pooched.
These are the AK30 batteries. 
Now..... I fly RC planes with electrics and batteries, some much bigger than these saw batteries. I'm not exactly sure if they are the same chemistry but assuming they are (LiPo).  There will be numerous cells (9 or 10) that must be balanced and run equally.  over time one cell can go bad which may not overly effect performance but can make it a safety hazard, as during charge or operating, that one bad cell may over charge to the point of catching fire, or discharge to a point it will be damaged and cause other issues within the pack.  
There could be some sort of lawyer made gadget inside the battery not allowing it to work so you don't burn your garage down. 
In the RC world on these high Capacity/high discharge batteries, i seem to think 500-1000 cycles is the expected lifespan.