Most boardview formats are a single file. ASC is different: it is a set of several text files that together describe the board, and a viewer needs all of them in the same folder. That catches people out when only one of the files is downloaded or when the set is split across folders. BVR is another format that turns up in collections, in more than one variant. This guide explains both and how to open them reliably.
ASC: a set of files
ASC boardviews are associated with Asus boards, and the format describes the board in several plain-text files with the .asc extension. A typical set includes separate files for:
| File (typical name) | Content |
|---|---|
| format.asc | Board outline and general format information |
| parts.asc | Parts and their positions |
| pins.asc | Pins, their positions and nets |
| nails.asc | Test points |
The exact names can vary, but the principle is the same: the viewer reads the whole set. The catalog lists boards with ASC files under .ASC boardview files, and Asus boards in general under Asus.
Opening an ASC set
- Keep all the .asc files together in one folder, exactly as they came.
- Open one of them — often format.asc or the first file of the set — in a viewer that supports ASC.
- The viewer loads the rest of the set from the same folder.
Supported viewers include OpenBoardView, whose installation is covered in OpenBoardView: Installation and First Steps, and FlexBV. If one viewer has trouble with a particular set, try the other; they are compared in FlexBV vs OpenBoardView vs Other Viewers: Which to Use.
Common ASC mistakes
- Only one file downloaded — the viewer shows nothing or reports an error. Get the whole set.
- Files renamed — some viewers expect the standard names. Restore them if a downloader changed them.
- Files from two boards mixed — if two sets were extracted into one folder, the viewer may combine them into nonsense. Keep each set in its own folder.
- Set inside an archive — extract the archive completely before opening.
BVR files
BVR is another boardview format found in repair collections, and it exists in more than one variant. Support depends on the viewer and its version:
- FlexBV reads many boardview variants and is a good first choice for BVR;
- OpenBoardView supports some BVR variants;
- if one viewer rejects a file, try the other and check that your viewer is up to date.
Because variants differ, a BVR file that opens in one viewer and not another is not necessarily damaged.
When a file will not open
| Problem | Likely cause | What to try |
|---|---|---|
| ASC set opens empty | Missing files in the set | Download the complete set |
| Error on opening | Wrong file selected, or renamed files | Open format.asc, restore standard names |
| BVR rejected | Unsupported variant in this viewer | Try another viewer or a newer version |
| Parts present, nets missing | Incomplete set or partial file | Look for another copy |
| File is an archive | Renamed by the source | Extract first |
The general troubleshooting list is in Boardview File Won't Open: Common Errors and Fixes.
Test points from the nails file
The test-point file is one of the most useful parts of an ASC set. Factory testers use these points to measure nets during production, so they sit on important rails and signals and are designed to be probed. In the viewer, test points usually appear as round pads with their own designators. When you need to measure a rail on a powered board, a test point on that net is often the safest place to put the probe: it is large, isolated and away from fine-pitch pins.
ASC in everyday Asus repair
Because Asus revises boards often, ASC sets are usually named after the board name and revision. Keep that naming when you store them, and when a board arrives, match its silkscreen name and REV to the set before opening. A practical habit is to open the set and immediately check two or three distinctive parts — a connector, a large inductor, the BIOS chip — against the real board. If they line up, the rest of the set will too.
Exporting and converting
Some viewers can export a loaded boardview to another format. That can help when you want to use a different viewer or share a single-file version, but it is rarely necessary for repair. If you do convert, keep the original set as well; conversions can lose test points, part outlines or other details.
Using the boardview once it opens
ASC and BVR boardviews behave like any other in the viewer:
- flip between top and bottom;
- search for part designators and net names;
- click a pin to highlight the net;
- use test points from the nails file to find probe locations.
Matching the file to your board
As with every boardview, confirm the board code and revision. Asus revises boards frequently, and an ASC set for a different revision can show parts in slightly different places. Compare the outline, connectors and a few distinctive parts before relying on positions.
Viewer versions matter
Boardview viewers add and fix format support over time. A file that fails in an old version may open perfectly in a current one, and occasionally the reverse happens with a regression. Keep your viewers up to date, and if a file that should work refuses to open, check the viewer's release notes or try the previous version before concluding that the file is damaged. Having two different viewers installed is the simplest insurance: what one cannot read, the other often can.
Organising multi-file formats
- Keep each ASC set in its own folder named with the board name and revision.
- Do not separate the files when copying or archiving them; zip the folder as a whole.
- Store the matching schematic in the same folder.
- Add a short text note with the source and date, so you can tell later whether a newer or corrected set might exist.
Example: an ASC that showed only an outline
An Asus boardview opens in a viewer but shows only the board outline — no parts, no pins. The folder contains format.asc and nails.asc, but no parts or pins files; the download source split the set into several archives and only one was downloaded. After downloading and extracting the remaining archive into the same folder, the board opens complete with all parts and nets.
FAQ
Why does an ASC boardview have several files?
The format stores outline, parts, pins and test points in separate text files. The viewer needs all of them.
Which ASC file should I open?
Usually format.asc, or any file of the set; the viewer loads the rest from the same folder.
Is BVR one format?
There are variants. Viewer support differs, so try another viewer if one fails.
Can I open ASC files in a text editor?
Yes, they are text. But a boardview viewer is needed to see the board.
Why does my ASC set show parts in the wrong places?
It may be for a different revision of the board. Compare it with your board.
Bottom line
ASC boardviews are sets of text files that must stay together in one folder; open one file and the viewer loads the rest. BVR comes in variants with uneven viewer support, so try another viewer before calling a file broken. In both cases, confirm the board code and revision before trusting positions.