Insights · Reverse engineering

When to reverse engineer obsolete hardware – and when to redesign

BLINKENLIGHT · ~5 min read

A board that has run a process line for fifteen years finally dies. The supplier dissolved. The design files never existed in any form you can find. The microcontroller went end-of-life two revisions ago, and the replacement part the OEM suggested isn't pin-compatible.

The question is rarely can this be fixed. It's which route is least risky for the next ten years.

This situation is more common than it sounds. Roughly 475,000 electronic components went end-of-life in 2023, with a similar figure the following year, and around thirty percent of those discontinuations happen without prior notice. Meanwhile, the equipment built around them is expected to run for twenty or thirty years. The maintenance burden lands somewhere between the OEM that no longer exists and the operator who depends on the board.

There are three sensible routes when an obsolete board fails. Picking the right one comes down to what's still recoverable, and what the surrounding system will tolerate.

Route 1 – Recover the documentation

Reverse engineer the existing board into a verified schematic, bill of materials and, where needed, board layout. The hardware behaves exactly as it did before, but it stops being a black box: you have the design data to maintain or repair the board, and to use it as the basis for the next two routes.

This is the right first move when the design is still sound and most of the parts are still available. The problem isn't engineering, it's lost knowledge, and reverse engineering restores what was lost. Route 1 is also the cheapest of the three, and it sets up the other two: you can't properly compare your options until you know what's actually on the board.

Route 2 – Build a compatible replacement

Recover the design, then re-spin the board to remove the obsolete parts while keeping form, fit and function the same. The connectors, mounting, timing and interfaces stay unchanged, so the surrounding system sees no difference.

This is usually the best value when only a handful of components are the problem. Maybe a microcontroller has gone EOL, or a power-management IC has been discontinued and the alternates aren't quite pin-compatible. Whatever the trigger, the work is bounded by a clear validation target: the new board has to behave indistinguishably from the original, which is a much easier brief than designing from scratch.

However, procurement teams often underestimate the challenge: a compatible replacement still needs careful matching on timing, noise floor and any analogue or RF behaviour buried in the original design. A typical obsolescence-driven board redesign sits between £20k and ₤80k, depending on how much of the original is RF or analogue and whether the project also has to produce regulatory documentation alongside the new board.

Route 3 – Redesign

Treat the obsolescence as the trigger for a deliberate new design. This is the right call when the original limits you on performance, cost, certification path or supply. A redesign also means absorbing a full validation cycle, and if the new product has to support a regulatory file (CE, UKCA, FDA, or a sector-specific equivalent), plan that work in from the start rather than at the end of the project.

The trap is treating Route 3 as the safe option because it produces something modern. A redesign costs more and takes longer than a compatible replacement, and the full validation cycle comes with the new design. Pick Route 3 because the new product is worth doing on its own merits, not as a reaction to obsolescence.

What drives the cost?

Whichever route you pick, two factors usually dominate. RF and analogue content is the biggest variable, since those sections need exact reproduction and close-enough substitutions don't work. Regulatory or market-entry documentation is the other: producing a file for a notified body changes both the validation plan and the deliverables. It's good to understand which of the two aspects will be the most complex before any engineering work starts, since the rest of the project shape follows from that answer.

Most obsolescence projects we take on begin by recovering the documentation and end with a compatible replacement. If that's the shape of your problem, our product & PCB reverse engineering services provide an end-to-end solution for obsolete products, including a review of IP boundaries and a full set of documentation to get you through the next ten years.

Book a free 30-minute consultation →

Published May 2026 · All insights