There are a variety of reasons PCB manufacturers, assembly houses and engineering departments put jobs on hold. Once a job is started, the parts are kitted up, boards are procured and assembly time is scheduled. When this process comes to a grinding halt because something is wrong, it costs the manufacturer or assembler time, which is typically passed on to the customer in the form of additional charges. The time frame for the fix determines if the job stays on the floor for a short time or if all parts are recalled back to stock, rebadged, and the partially assembled boards go back in storage.
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