Voting rights activists want independent experts to test the touch-screen machines to determine where and how the problems arose. Summary tapes in dozens of machines were off by one vote when compared with other internal controls.
The subpoenas are part of a lawsuit trying to force the state to scrap 10,000 electronic voting machines in use throughout New Jersey.
The activists say the machines, most made by Sequoia Voting Systems, are unreliable and prone to hacking.
Problems during the presidential primary were reported in Bergen, Gloucester, Mercer, Middlesex, Ocean and Union counties.
A letter from Sequoia's lawyer says the company will try to have the subpoenas quashed.
