Electronics troubleshooting and design review: the cause confirmed by measurement, the correction verified by test
Micro Digital Engineering investigates electronics that fails, overheats or behaves unpredictably — prototypes, products returned from the field and units from equipment in operation — and reviews designs developed by other teams. Our investigation is evidence-led: we reproduce the fault where possible, test potential causes, document confirmed findings and verify agreed corrections. Unresolved hypotheses are reported separately.
Confidential task? We sign an NDA before you share technical files.
Can you find why our prototype fails or behaves unpredictably?
Yes. The investigation follows a fixed sequence: the symptom is reproduced and recorded, the design and measurements are analysed, the cause is identified and confirmed, corrective changes are made, and the result is verified by repeat tests under the same conditions.
Diagnosis, design review and corrective changes
| Work | When you need it | What you receive |
|---|---|---|
| Failure diagnosis | A device fails, overheats, resets or behaves differently from unit to unit | The confirmed root cause, with the measurements and tests that prove it |
| Independent design review | A design from another team has to be assessed before production or further development | Ranked findings, each with its evidence, and recommended changes |
| Corrective changes | The cause or the review findings are known | Changes made on the boards or in a new revision, verified by repeat tests |
Each can be ordered on its own. A diagnosis usually ends with the findings and proposed changes; implementation and verification follow as the next stage.
When you need this
- A prototype fails tests or behaves differently from unit to unit.
- Products fail in the field and the cause is not known.
- A board or power stage overheats.
- Equipment resets, locks up or behaves unpredictably under certain conditions.
- A design developed elsewhere has to be reviewed before production or before continuing development.
Typical problems
- Failures of components or whole boards.
- Instability: resets, lock-ups, oscillation, intermittent faults.
- Overheating and thermal problems.
- Failures of converters and power stages under load — see also power electronics design.
- Faults where firmware and hardware interact, such as protection that trips or does not trip.
- Interference and signal integrity problems — described in detail on EMI troubleshooting.
- Problems that appear only with specific loads, temperatures or connected equipment.
What counts as a result
The symptom is reproduced
The conditions are recorded — supply, load, temperature, connected equipment, firmware version — so that the fault can be repeated and the later tests can use the same conditions.
The cause is confirmed
A hypothesis is accepted as the cause only when a measurement, a test or a controlled change confirms it. Unconfirmed possibilities are reported as such.
The correction is defined
Changes to the schematic, layout, components or firmware are listed with the effect each is expected to have.
The result is verified
Repeat tests under the original conditions show whether the symptom is gone and whether the change has affected anything else.
What a design review covers
- Schematics: component ratings and margins, protection, power supply and start-up behaviour.
- Layout: power and ground, current paths, thermal design, isolation distances, critical routing.
- Components: suitability, availability and lifecycle status.
- Firmware, where it controls protection or critical functions.
- Manufacturability and testability of the board.
Findings are ranked by their consequences, and each is supported by analysis, calculation or measurement.
Where the work is done
Measurements, rework of boards and repeat tests are carried out in-house by our engineering team. When a correction needs a new PCB revision, the bare boards are fabricated by a specialised manufacturing partner, then assembled and verified in-house.
Calibrated laboratory measurement capabilities
Our laboratory performs electrical measurements, waveform analysis and functional verification using calibrated measurement equipment. All measurement instruments have undergone calibration (etalonare) and are supported by calibration certificates.
For diagnosis this includes oscilloscope measurements, voltage, current and frequency measurements, component measurements and tests under the conditions in which the fault occurs.
The applicable measurement ranges and test conditions are defined according to the engineering task.
What’s included
Recording and reproduction of the symptom, analysis of schematics, layout, firmware and measurements, identification and confirmation of the cause, proposed corrective changes, implementation of the changes when agreed, and verification tests. A design review can be ordered on its own.
Not included: repair of consumer appliances, general audits of industrial assets, and official certification testing.
What you receive
| Deliverable | Format | How it is checked |
|---|---|---|
| Findings report | Document with ranked findings | Each finding with evidence: measurement, analysis or test |
| Root cause | Section of the report with the confirming measurements | Reproduction or controlled change |
| Corrective changes | Change list: schematic, layout, components, firmware | Design review |
| Corrected boards or new revision, when agreed | Reworked boards or boards of the new revision | Repeat tests |
| Verification report | Document | Repeat tests under the original conditions |
How the work runs
- The symptom is reproduced and recorded.
- Design documents, firmware and measurements are analysed.
- The cause is identified and confirmed.
- Corrective changes are proposed and agreed.
- The changes are implemented on the boards or in a new revision.
- The result is verified by repeat tests.
See how we work.
What to send us
- A description of the problem: when it happens and under which conditions.
- Schematics, PCB files and firmware, if available.
- Test results, logs or photos of failed parts.
- The number of units affected.
- Samples, once we have agreed how to handle them.
Common questions
Can you work without our design files?
It is possible, but slower: the board has to be analysed first, as described in PCB reverse engineering. Design files make the investigation faster and more precise.
Can you review a design that has not failed yet?
Yes. An independent design review is a separate order and is often done before a design goes into production.
Do you only report, or also fix the problem?
Both are possible. The first stage usually ends with the findings report and the proposed changes; implementation and verification follow as the next stage.
How long does a diagnosis take?
It depends mostly on how easily the fault can be reproduced. The first stage has a defined scope and result; intermittent faults may need a longer observation agreed in advance.
What if the board cannot be fixed economically?
Then a replacement is the better route. See obsolete electronics replacement and redesign.
Related services
- EMI troubleshooting — interference and signal integrity.
- Power electronics design — redesign of a power stage after the cause is found.
- PCB design — layout corrections and new board revisions.
- Embedded firmware — firmware corrections.
- Obsolete electronics replacement — when repair is not the right answer.
Describe the problem
Tell us what fails, when it happens and what you have already checked.
Confidential task? We sign an NDA before you share technical files.