Martin Logan ESL Expression 13a amp removal, woofer not working

Easy to remove. Unscrew feet, use 1/2 inch hexwrench to remove where the feet were screwed into. Seperate(easiest if speaker laying on side), disconnect 2 connectors. Vwa lah.

Droleg.  Tried that but feels like it’s connected somewhere else up in there. So I don’t have to remove the side rails?

No. Just the 4 thingys. Then it just jiggles out. Did it on mine several times, for different reason than yours , though.

If you go on ml website/support, you may find the instructions. They sent them to me, but not sure where they are.

I don't know this amp but most subwoofer amps are similar inexpensive class D amps (not critcizing, that is quite adequate for bass frequencies).  I've replaced amps in subwoofers the blew.  I think the one I ordered from HSU was about $250 and took 10 minutes to install.  

I'm guessing something in the channel is overheating.  could be a defective thermal overload ($2 part).   when you get the amp out you may see obvious signs of overheating.  if not, ask ML how much it costs for them to just send you a replacement amp.  You may be surprised.

If it was mine, I would troublshoot it myself and likely fix it for $10 or less but to pay someone to do the troubleshooting will likely cost more than the price of a new amp.  Yes, that is the service industry world we live in.  I recommend every young person study physics and become self sufficient.  I've yet to have one take my advice.

Jerry