In short: Install OpenBoardView (free, Windows / macOS / Linux) — it opens .brd, .bdv, .bv, .bvr, .cad, .fz, .asc, .cst and .f2b files directly. Use BoardViewer or FlexBV for Tebo .tvw files that OpenBoardView cannot read, and the Cadence Allegro Free Physical Viewer for native Allegro .brd databases.
The short answer
| Extension | Typical boards | Free viewer that opens it |
|---|---|---|
.brd |
Apple, Lenovo, many others | OpenBoardView |
.bdv |
HP, Sony, Foxconn-built boards | OpenBoardView |
.cad |
Compal, Quanta, Wistron (Dell, HP, Acer, Lenovo) | OpenBoardView |
.fz |
ASUS, ASRock, Pegatron | OpenBoardView (needs the FZ key) or BoardViewer |
.asc |
ASUS (folder of several files) | OpenBoardView |
.tvw |
Gigabyte, MSI, newer laptops | BoardViewer, FlexBV |
.bvr, .bv, .cst, .f2b |
Lenovo, MSI, Clevo, older boards | OpenBoardView |
.pcb |
Phones, recent laptops (XZZ) | XZZ viewer, recent OpenBoardView / FlexBV |
There is a page for every extension in the format reference.
Set up OpenBoardView
- Download the latest release from openboardview.org and unpack it — there is no installer.
- Start the program and drag the boardview file onto the window, or use File → Open.
- Press Ctrl+F (or just start typing) and enter a component name such as
PQ12or a net name such as+3VALW. The view jumps to the part and highlights every pad on the same net. - Press Space to flip the board and see the other side.
Useful keys: mouse wheel zooms, right-drag pans, R rotates, M mirrors, N opens the net list.
When a file does not open
“Unknown file format” on a .brd. The extension is shared by several unrelated formats. Open the file in a text editor: readable text means a repair boardview that should load; binary content and a size of tens of megabytes means a native Cadence Allegro database, which needs the Allegro Free Physical Viewer.
An .fz file opens as an empty board. FZ files are encrypted. OpenBoardView needs the FZ key entered once in its settings file; BoardViewer and FlexBV have it built in.
An .asc file loads only partly. ASC boardviews are a set of files (format.asc, parts.asc, pins.asc, nails.asc). Unpack the whole archive into one folder and open any one of them.
A .tvw file fails in OpenBoardView. Tebo files exist in several versions. Try BoardViewer or FlexBV, both of which have broader TVW support.
The archive contains only a PDF. That is a schematic, not a boardview. Search Enginerys for the same board number and filter by Boardviews.
Work with the schematic side by side
A boardview tells you where a part is; the schematic tells you what it does. Open the PDF next to the viewer, search the schematic for the net you are chasing, then type the same net name into the boardview to see every place it can be probed. FlexBV can link the two so that a click in one moves the other.
Boardviews are built for one exact board revision. If component names in the viewer do not match the silk-screen on your board, you have a file for a different revision — search again with the full board number, including the revision.