J&K Custom Electronics is an Electronic Contract Manufacturing (ECM) business, providing Electronics Manufacturing Services (EMS). ​Our typical customer contracts our services to populate Printed Circuit Boards (PCB) with Surface Mount Technology (SMT) and Through-Hole Technology (THT) components. Populated assemblies may then be conformal coated, have wires added, often programmed, and ALWAYS FUNCTIONALLY TESTED FREE prior to final system assembly into a unit or an enclosure. ​ ​Only J&K Custom Electronics is so committed to deliver 100% working electronics that we back up our workmanship with a THREE YEAR GUARANTEE ON WORKMANSHIP, we offer FREE customer supplied functional testing on all electronics. Customers supply functional test method and Hardware..