Mobile for head bald for head HD870 single for head generation SF-HD62 65 The for head has electrostatic for protection solder joint. Before use, please use an anti-static soldering iron to heat, then pull outPlug, and open the for protection solder joint (silver tinPoint) on the for head It must be completely disconnecte, otherwise the disc will not be read without light, and the for head objective lens must not be touched/falled during the installation process, and the potentiometer must not be adjusted by yourself All product in our shop are shipped after factory testing is OK, and theQualityControl is very strict It will cause the for head to burn the tube! It is recommended that non-technical personnel purchase movement directly, the replacement is simple and and the for head cannot read the disc due to incorrect installation