EXHIBIT 23.1 CONSENT OF INDEPENDENT CERTIFIED PUBLIC ACCOUNTANTS We have issued our report dated October 24, 1997 accompanying the consolidated financial statements and schedule of Allied Digital Technologies Corp. and subsidiaries contained in the Registration Statement and Prospectus. We consent to the use of the aforementioned report in the Registration Statement and Prospectus, and to the use of our name as it appears under the caption 'Experts.' GRANT THORNTON LLP Melville, New York June 4, 1998