The .brd extension is used by several completely different file formats. Some .brd files are boardviews made for repair; others are the original PCB design files from professional design software; others again come from hobbyist tools. They are not interchangeable, and a viewer that opens one will refuse another. The first step with any .brd file is therefore to work out which kind you have. This guide shows how, and which program opens each kind.
The main kinds of .brd
| Kind | Origin | Typical content | Opens in |
|---|---|---|---|
| Test_Link boardview (plain text) | Repair boardview format | Parts, pins, nets in readable text | OpenBoardView, FlexBV |
| Test_Link boardview (scrambled) | Same format, encoded | Unreadable text, same structure | OpenBoardView, FlexBV |
| Allegro design file | Professional PCB design software | Full binary design database | Design viewers; FlexBV for some versions |
| Eagle board | Hobbyist and small-scale PCB software | XML text | Eagle or compatible tools |
For laptop repair, the first two are by far the most common. The catalog lists boards with BRD files under .BRD boardview files.
How to tell which one you have
Open the file in a plain text editor (not a word processor) and look at the start:
- Readable text with section headers such as file format, number of parts, nets and pins — a plain Test_Link boardview.
- Random-looking characters but a text-like structure of lines — a scrambled Test_Link boardview.
- Binary content with a recognisable design-tool header — a design database such as Allegro.
- Starts with an XML declaration and mentions Eagle — an Eagle board.
You do not need to understand the content; the first few lines are enough to identify the kind.
Opening Test_Link boardviews
Both plain and scrambled Test_Link files open in:
- OpenBoardView — free and open-source. Installation and first steps are covered in OpenBoardView: Installation and First Steps.
- FlexBV — commercial, with additional features. The two are compared in FlexBV vs OpenBoardView vs Other Viewers: Which to Use.
Drag the file onto the viewer or use File → Open. The viewer recognises the format automatically.
Opening design-tool files
Original design files are much richer than boardviews — they contain copper layers, traces and full layout — but they need software that understands the design tool's format:
- the design tool's own free viewer, where one exists;
- FlexBV, which reads some versions of these files;
- a conversion to a boardview format, done with tools that support it.
If an ordinary boardview viewer rejects a .brd, it is often this kind of file.
Opening Eagle files
Eagle board files are rare in laptop repair collections. They open in Eagle itself or in tools that import Eagle designs. They are unlikely to be a laptop boardview at all; check whether the file is for something else that was mislabelled.
Common problems
| Problem | Likely cause | What to try |
|---|---|---|
| Viewer says the format is unknown | Design-tool or Eagle file, not a boardview | Identify the kind as above; use the matching tool |
| File opens but is empty or garbled | Damaged download or truncated file | Download again, compare sizes |
| File is really a compressed archive | Renamed by the source | Extract it first |
| Parts appear, nets missing | Partial export | Look for another copy |
A general troubleshooting guide for all formats is in Boardview File Won't Open: Common Errors and Fixes.
Working with a BRD once it opens
- Flip sides to see bottom-side parts.
- Search designators from the schematic.
- Click a pin to highlight the whole net.
- Check the outline against your board to confirm the revision.
Boardview formats in general are compared in Boardview File Formats Compared: BRD, BDV, FZ, CAD, TVW, ASC.
What a design file adds
When a .brd turns out to be the original design database, it can be more valuable than a boardview. Besides parts and nets, it contains the copper itself: traces on every layer, vias, planes and the board stack-up. That lets you follow a signal through inner layers, see exactly where a trace runs under a chip, and find a broken connection that a boardview could only hint at. The cost is that it needs a capable viewer and more care to navigate. For most repairs, a boardview is enough; for difficult inner-layer faults, a design file is worth its extra effort.
Plain and scrambled files in practice
Plain and scrambled Test_Link files contain the same kind of data and behave identically in the viewer. The scrambling only affects how the file looks in a text editor. There is no need to decode a scrambled file yourself; if the viewer opens it, everything is there. If you want to check what a plain file contains, the text sections for parts, pins and nets are easy to read and can confirm the board name or part count before opening.
Why the same extension is used for different things
File extensions are just a naming convention. Different tools chose ".brd" independently because it stands for "board". Nothing stops two formats from sharing it, and repair collections often contain all of them under one extension. Identifying the content, not trusting the extension, avoids hours of frustration.
Checking a BRD before you rely on it
Even a file that opens perfectly can be the wrong one. Before measuring from a BRD, compare its board outline, connector positions and a few distinctive parts — the BIOS chip, a large inductor, the DC jack — with your board. If two or three landmarks match, the rest almost certainly does too; if one is missing or moved, look for a file for a different revision.
Organising BRD files
Rename files to include the board code and revision, and add a note of the kind — for example "boardview" or "design file" — so you do not have to inspect them again. Keep the matching schematic alongside.
Example: the BRD that OpenBoardView rejected
A file named with a board code and the .brd extension refuses to open in OpenBoardView, which reports an unsupported format. In a text editor, the first bytes are binary with a recognisable design-software header — it is an original design database, not a boardview. Opening it in a viewer that supports that design format shows the full layout, including copper traces, which turns out to be more useful than a boardview for tracing a broken inner-layer connection. The file was never broken; it was simply a different kind of .brd.
FAQ
Why will my .brd file not open in OpenBoardView?
It may be a design-tool or Eagle file rather than a Test_Link boardview. Check its content.
Is a scrambled BRD file damaged?
No. Scrambled Test_Link files are encoded on purpose; boardview viewers decode them.
Which is better, a boardview or a design file?
A design file contains more information, but a boardview is enough for most repairs and opens in free viewers.
Can I convert a design file to a boardview?
Some tools can. For repair, opening it in a capable viewer is usually simpler.
How do I check the revision in a BRD file?
Compare the outline and distinctive parts with your board, and check the file name for the board code and revision.
Bottom line
A .brd file can be a plain or scrambled Test_Link boardview, a professional design database or an Eagle board. Look at the first lines in a text editor to tell which, open boardviews in OpenBoardView or FlexBV, and use the right design tool for the others. Then confirm the file matches your board's code and revision.