Speaker internal amp shutting off due to heat

The obvious question is have you talked to Martin Logan about this?  Clearly there is a problem somewhere and I'd assume they would recommend replacing the internal amp.

What kind of monster can listen to music in 85 degrees??  

Ok, seriously though, may just not be designed to run in such heat. Talk to ML and consider a fan on the back of the units. If they are 100% sealed they may do all their cooling through the back plate. 

80 degrees (or 27C) is about the rated ambient temperature for the active components in an amplifier so that in itself is not likely the issue. Amplifiers usually have a temperature sensing system comprised of heat sink thermostats and associated circuitry. If the thermostat is faulty it will open at a lower (or higher) temperature and activate shutdown. Or it could be a circuit element (transistor, zener and steering diodes or capacitor) that is faulty and triggering the shut down. The thermostat (a $10 part)  is the easiest to replace; a schematic would be necessary to troubleshoot the circuit. 

Hi , totally random thought. Are they receiving enough current? I’ve seen issues occur in unrelated applications where power cable was too light and or too long. I’ve had low voltage ruin my air conditioner. Just a random thought about low amperage and/or low voltage. Cheers , Mike. 

I've talked to ML before and replacing the 2 amp modules is about $600. But they recommend replacing the entire thing for $1k. 

@buellrider97 I have troubleshoot with all sort of cables. None helped. Basically I've troubleshoot it to the point where I know exactly which day the amp would shutoff and which day it would operate normally.

As stated in the initial post. There's another identical speaker that is operating flawlessly.

@gs5556 What you said was very helpful and was in line of information I was hoping for, thanks.

@erik_squires a Gila Monster?