Primitive servo failure!

Though I had no intention to check it deeply at the beginning, just loosening I was 4 screws at the lower corners of the malfunctioned servo, then I found it!
Now feel I lucky that I didn't loose or destroy my lovely PILOT Ace B with critical failure on the most important elevator driving servo, those strange reaction happened not only yesterday but also today.
Soldering error was the criminal of the affair today. The symptom was loosing control while the flight only at motor high speed condition. Just replacement of the servos was my work today after the morning flight, checked I the ill-servo by chance. Micro servo as it is, it is worth using because of the basic construction, metal gears and 2 ball bearing driving shaft support design. This removed one would be reused in PILOT Junior, elevator and rudder driving.