Aastra ROF1376303/1 – DC/DC MX-One Board

Overview

The Aastra ROF1376303/1 is a DC/DC power board used in Aastra (now Mitel) MX-ONE Classic telephony subracks, responsible for distributing and converting the system’s main −48VDC supply into the regulated voltages that device boards require to operate. It is a core power-distribution component rather than a communication or line card, sitting between the AC/DC power system and the equipment backplane.

As a maintenance and spares item for existing MX-ONE Classic installations, the ROF1376303/1 remains a relevant replacement part for facilities keeping legacy Aastra/Mitel telephony infrastructure in service. Seven Star LLC supplies the Aastra ROF1376303/1 as a parts partner to telecommunications and facilities teams across Oman and the GCC.

Operating Principle

The ROF1376303/1 receives the system’s −48VDC main supply and distributes it to the MX-ONE Classic backplane, while also generating the regulated ±5V and ±12V DC rails that device boards in the subrack require for their internal logic and interface circuits. By centralizing this voltage conversion on a dedicated board, the MX-ONE Classic architecture keeps individual device boards simpler, relying on the DC/DC board for clean, regulated power.

Engineering Design of the Aastra ROF1376303/1

The board is designed to slot directly into an MX-ONE Classic subrack, converting the incoming −48VDC feed into the multiple regulated voltage rails the backplane’s device boards depend on. When a third-party AC/DC power system is used upstream instead of Aastra’s own, the installation documentation specifies a maximum 15-ampere fuse rating to protect the DC/DC board and downstream circuitry from overcurrent conditions.

Key Features

• Distributes −48VDC main supply to the MX-ONE Classic backplane
• Generates regulated ±5V and ±12V DC output rails
• Direct fit for MX-ONE Classic subrack architecture
• Supports third-party AC/DC power systems with a 15A fuse limit
• Centralized power conversion simplifies device board design
• Genuine Aastra/Mitel replacement part for legacy systems

Industrial Applications

The ROF1376303/1 is used to maintain existing Aastra/Mitel MX-ONE Classic telephony installations across offices, control rooms, and facilities in Muscat, Sohar, and Salalah that have not migrated to a newer communications platform. As a power-distribution board, its failure can take an entire subrack of device boards offline, making it a critical spare to keep on hand for these systems.

Across the GCC, facilities and IT teams supporting legacy enterprise telephony infrastructure rely on genuine replacement boards like the ROF1376303/1 to avoid extended downtime on communication systems that remain in active service, particularly where full platform replacement isn’t immediately planned or budgeted.

Technical Specifications

Request a Quote for Aastra ROF1376303/1 – DC/DC MX-One Board

Contact Seven Star LLC for pricing and availability on the Aastra ROF1376303/1 DC/DC MX-ONE power board and other legacy telephony spares across Oman and the GCC.