I ordered several RAMPS board from aliexpress and amazon, and get two of them not working for me, one is overheat and the other came with bowled fuse, I contacted the seller and get replacement very quick, however, the overheat one replacement have bowled diode, and I got replacement again. The amazon one did not even ask me to send back the faulty board, just ask me send video to prove the board is not functional with correct wiring.
the material cost of these boards in China are unbelievable low, the cost of sales and shipping and customer service is 80%-90% of the final price, and among the material cost, the main chips cost 70% of them if imported from Japan, Koean, or Taiwan.
(Da Vinci 1.0, Jr. 1.0 RAMPS, miniMaker) X4, (Creality CR-10S, CR-10 mini, Ender-3) X4, Anycubic MEGA X4, Anycubic Chrion X1, ADMILAB Gantry X2 (MonoPrice Maker Select V2, Plus, Ultimate)X4--Select mini X1, Anycubic photon X4, Wanhao duplicate D7 X1.
iNSTONE Inventor Pro X2, CTC Dual X2, ANET-A8, Hictop 3DP-11, Solidoodle Press, FLSUN I3 2017X1