How to Flush Drain Line on GE Monogram Built In Side-by-Side

Refrigerator & Freezer Repair
1

GE repair has tried 4 times, each time "fixing" something, only to find that the root cause is something else. The last guy may have found the root cause, but I suspect he didn’t do a good job getting it fixed adequately.

  1. Freezer ran too cold, cooler ran too warm. GE repairman noticed major ice buildup at the top of the freezer, blocking the fan that pushes cold air from the freezer into the cooler. He de-iced the freezer, changed the fan, and replaced the drain trough as that was also damaged due to the ice build-up. Cost: ~$600!
  2. Issue remained, so he came back and changed a thermostat in the mid-section of the freezer.
  3. Issue remained, so a second guy came. Diagnosis: ice remains in the wall between the freezer and the cooler. Recommendation: turn off the fridge / defrost for 3 days.
  4. Worked OK for about a week, then condensation started to appear in the cooler, on the wall adjacent to the freezer. Condensation got worse over time, to the point that water was building up in the crisper. Then back to square one, the freezer ran too cold, the cooler ran too warm.
  5. New GE repairman’s diagnosis: something (the drain line?) is blocked, so moisture doesn’t make it to the evaporator pan (evidence: evaporator pan is bone dry). Instead, water builds up in the wall in between the freezer and the cooler, freezes up and blocks cold airflow from freezer into the cooler. He spent about 5 minutes cleaning out (the drain line?) with a turkey baster-like tool. Then recommended defrost for a day.
  6. Five days later, the temperature is fine in both compartments and there is minimal sign of condensation. But the evaporator pan is again bone dry continually.
    Where is the drain line? I see some sort of insulated tubing running from the sealed box compartment on the left, going through the middle divider towards the right side where the compressor sits (but I can’t see the tubing passed the divider as there are a bunch of other stuff in front of it) – is this the drain line? More importantly, where can I find its entry point in this model in order to flush it out? Anything else I should do?