Pitch, Position, and Contact Side — the BOM Fit Check
The SFW10R-4STE1LF: It is a top-contact design (contacts, top), meaning the flex cable's conductive pads must face upward when inserted into the right-angle SMT housing. A flipped flex shorts the wrong row — confirm the cable orientation before actuating the slide lock.
ZIF Actuation and Cable Thickness — What the Slide Lock Expects
Zero Insertion Force (ZIF) with a slide lock: the actuator opens the contact beams, the cable slides in with no force, and the lock closes to clamp the flex. The connector accepts FFC or FPC with a notched, tapered end and a thickness of 0.30 mm or 0.33 mm — match the cable thickness to the actuator; a 0.30 mm cable in a 0.33 mm slot may not lock reliably.