Okidata 50099501 Printhead ML 520 ML 521 Microline Dot Matrix Printer Head

Okidata 50099501 Printhead ML 520 ML 521 Microline Dot Matrix Printer Head

The Okidata 50099501 is an OEM dot matrix printhead designed for the Microline ML 520 and ML 521 series printers. This is a direct replacement for the original printhead assembly — the component responsible for striking the ribbon against the paper to form characters and graphics in a dot matrix pattern. It features an aluminum finned heat sink body to manage thermal output during operation, a flex PCB ribbon connector for interfacing with the printer's main board, and the front-mounted ink guide/nozzle assembly.

Specifications & What's Included

• Part Number: 50099501
• Compatible Models: Okidata Microline ML 520, ML 521
• Type: Dot matrix impact printhead
• Construction: Finned aluminum heat sink body with flex PCB (FPC) ribbon connector
• Date Code: BB04-05 (visible on flex ribbon)
• Printhead only — no cables, ribbon, or mounting hardware included

Applications

The Okidata Microline ML 520 and ML 521 are narrow-carriage 9-pin dot matrix printers that have been widely used in point-of-sale, light industrial, and multi-part form printing environments. The printhead is the primary wear item in a dot matrix printer — it strikes an inked ribbon thousands of times per minute and eventually requires replacement. The ML 520/521 series remains in active use in legacy business environments where multi-part carbonless forms, time-stamped logs, or offline/serial-port printing are still required. Replacement printheads for these models can be difficult to source new, making a pulled-from-service OEM unit a practical and cost-effective solution for repair shops and end users keeping these printers running.