Need help diagnosing an intermittent problem. Refrigerator trips circuit breaker every few hours for a couple of days then works normally for a few months. Unit is Frigidaire FPHF2399MF0 purchased new in 2011. (French door unit with ice maker in upper fresh food compartment). Used indoors.

Unit continues to cool well as long as it is powered. After restarting, if either compartment was too warm, the unit cools them down as quickly as can be expected (an hour or so). Sounds fine. None of usual symptoms other than the cube/crush selector is stuck at crush.

Some (or lots of) history:

Oct 2017(?):
-Ice dispenser only dispensed crushed ice after re-installation after remodel, but we ignored it.

1st week Feb 2018:
-Found fridge off and breaker tripped. Reset breaker and unit ran for 3-8 hours before tripping again. This continued for a few days.
-Switched off ice maker during this period in an attempt to eliminate unnecessary load.
-Meanwhile, ran fridge on other circuit which also tripped breaker. Seems house wiring ok, Fridge is the problem.
-Repair guy came, visually checked the control board, which he thought was fine so he figured the compressor was going bad, expensive repair => just buy a new one. (Later learned that he actually checked the inverter board for the variable speed compressor, not main control board). Repair guy cleaned the very dusty coils.
-Unit tripped breaker maybe one or two more times since then and then ran normally...
-Turned ice maker back on at some point.

1st week May 2018:
-Again, found fridge off and breaker tripped. Reset breaker and unit ran for 3-8 hours before tripping again. This continued again for a few days.
-Switched off ice maker again in an attempt to eliminate unnecessary load.
-Tried the unit's diagnostic mode. Tested all components individually. Cube/Crush solenoid still did not work. Switching on defrost heater tripped the breaker one time, but could not replicate in subsequent attempts.
-Next day, tested functions in diagnostic mode while measuring current draw in the main AC cable. Nothing seemed unusual, but I don't know the expected current draw. Compressor: 2.0A, Ice Auger motor (no ice): 3.0A, Defrost Heater 5.0A. Ran unit overnight, max draw 2.0A. No more breaker tripping -> So these measurements may have been taken without the fault present.
-Inspected main control board, a loose piece fell out upon removal, it was a chip off of a small transistor controlling the cube/crush solenoid. Measured voltage to solenoid at connector near icemaker, 7.9VAC in either cube or crush. Manually moving the solenoid latch felt no different if it was turned off or on.
-Freezer defrost heater measured ~230Ohms, measured at main board connector. Ice maker defrost heater measured 20Ohms, measured at ice maker connector.
-Compressor coils measured 17.3/17.3/17.7 Ohms.

Outside back panel has rusty streak which starts behind the ice maker defrost drain. I think this was always there. If so, it could be due to condensation rather than a leak.

Questions:
Any ideas on what else to check? Or how to replicate? I'm not sure how long the ice maker had been back on before the problem occurred again. At least a month or more?

The cube/crush solenoid/transistor are obviously a problem but could that be the root cause of the breaker tripping? I could replace the main board and/or cube/crush solenoid, but I'm not confident that either caused the breaker to trip given that it runs normally for months in that condition.

Since it runs a while before tripping, I'm suspicious of the defrost cycle.
I'm wondering if keeping the ice maker off might be allowing the problem to right itself, even though the ice maker coils/fan are still cooling that compartment.