I suggest not sending the amp to Mikhail as long as the problem is intermittent. Mikhail takes long enough to fix a known problem and may take a long time by his measure to debug this problem.
You're doing the right thing by letting Mike take it for a while. Also, if you want to your engineering buddy to take a look at it, you can open it up so he doesn't have to worry about scratching your amp. You'll need a 1/16" hex wrench to get the screws out. Just be sure that the amp is not plugged in and has been off for several hours so that the caps have all had time to discharge. Then don't touch anything inside the amp anyway.