I recently sent main boards from  S17 Antminers to HK for repair
This is my experience 

Disassembly easy
Outbound package 2Kg $300 via DHL 👀 
Delivery to Bitmain in HK 2 days
Quote &amp; repair $60 - 4 days
Return to 🇿🇦 via UPS $30 - 4 days

Total $390 10 days