SYNC on cdj3000

Yes. If all four of the CDJ-3000 are using their own USB/pendrive and all part of the same PRO DJ LINK network (each CDJ connected via ethernet cable to same hub/switch) then they can all SYNC together. not sure what you mean by "without link" but PRO DJ LINK among other things, allows PRO DJ LINK-capable devices to share USBs (or each device can have their own USB to play from), SYNC at the BPM, Beat or Bar level & quantise BEAT FX on a PRO DJ LINK-capable DJM mixer, among other things. hope that helps;/

mmm my engisht isnt the best

what im trying to say is, if i use 4 pendrives 1 on each CDJ but WITHOUT link, sync works? i mean, SYNC works with track from CDJ 1 with track from CDJ 2 without using link cable? or to use SYNC i need to have the CDJ on link yes or yes? 

if two CDJ players (or four players) are NOT connected/linked via ethernet cables (ie. PRO DJ LINK network), then SYNC and any other PRO DJ LINK feature will not work. and if each CDJ had its own usb connected with tracks, it would be the equivalent of DJing on CDJs using CDs or mixing records on turntables, from a mixing/beatmatching perspective.