The four rules
If you remember nothing else from this page, remember these. They account for the overwhelming majority of cards that a controller will not read.
| Rule | Why |
|---|---|
| Card of 32 GB or smaller | Larger cards use a file system the controller cannot read |
| Formatted as FAT32 | exFAT and NTFS are rejected outright |
| Files in the root of the card | The controller looks in one place only; it does not search folders |
| Nothing else on the card | Leftover files from a previous job confuse the playback |
These are not preferences. A card that breaks any one of them will fail, usually without a helpful error message — the controller simply sits there doing nothing, which is why people spend an hour checking their wiring first.
Choosing the card
Bigger is not better here. The controller reads the card with simple firmware that expects a straightforward file system, and modern high-capacity cards are formatted in a way it cannot handle.
- Size: 32 GB is the ceiling. Smaller cards work perfectly well — a show file is small, and there is no benefit to extra capacity.
- Brand: buy from a reputable brand through a reputable seller. Counterfeit cards are common and they fail unpredictably, which is the worst kind of failure because you cannot reproduce it in the workshop.
- Speed class: a mid-range class is more than sufficient. You are not recording video.
- Spares: carry at least two written cards to every job. Cards fail, and the spare costs less than the reputation damage of a dark display.
Set aside one card you know works, label it, and never use it for anything else. When a new card fails, swap in the reference card. If the reference works, the problem is the card. If it does not, the problem is elsewhere and you have just saved yourself an hour.
Formatting it properly
Deleting the old files is not the same as formatting. Deleted files leave the file system exactly as it was, so if the card was exFAT before, it is still exFAT after you empty it. Format properly every time.
Insert the card and open the format dialog
In Windows, open File Explorer, right-click the card's drive letter, and choose Format. Check the drive letter twice before you continue — formatting the wrong drive is not recoverable.
Select FAT32
Choose FAT32 in the file system list. If FAT32 is not offered, the card is too large — use a smaller card rather than looking for a workaround.
Uncheck quick format
A full format takes a few minutes longer and rebuilds the file system properly. On a card that has been used before, this is worth doing. It also flags a failing card, because a full format on a bad card will report errors.
Eject the card and reinsert it
Confirm the card shows as empty and reports the expected free space. If it does not, something went wrong — repeat the format before continuing.
Formatting a pen drive or external disk by mistake destroys everything on it, and there is no undo. Confirm the letter, confirm the reported capacity matches the card, then proceed.
Writing the files
Confirm your hardware settings first
Controller model, IC type, pixel count and layout must all be correct before you export. The exported file is built from these values. Change any of them afterwards and the file on the card no longer matches the fixture.
Preview the show one last time
Watch the full loop in the preview window. This is your last chance to catch a jump at the restart or an effect that does not reach the end of the fixture. See our TOL file guide for what to look for.
Run the export
Open the export or output option and select the SD card as the destination. Let the software name the files itself — the controller expects specific names and renaming them stops playback.
Do not remove the card while it is writing
Wait for the software to report that the write has finished, then eject the card properly through Windows rather than pulling it out. A card removed mid-write produces files that look present but are incomplete.
Check what actually landed on the card
Open the card in File Explorer. The exported files should be sitting in the root, visible immediately, with a sensible file size. Files inside a folder will not play. A file of zero bytes means the write failed.
Testing before the job
Never let a card go to a venue untested. Keep a short test strip and a spare controller on the bench for exactly this purpose.
- Insert the card and power the controller. It should begin playing on its own within a few seconds. If it does not, the card is the problem, not the fixture.
- Watch a complete loop. Check the restart is clean and the timing is what you expected.
- Check the colours. If red comes out green, the signal order is wrong — fix it and re-export. Our troubleshooting guide covers this.
- Power cycle once. Switch off and on again. The show should restart by itself. A card that only plays the first time will fail at the venue.
A show exported for 800 pixels behaves differently on a 50-pixel test strip. The test tells you the card is readable and the colours are right; it does not confirm the timing. Where the job is large, test against the actual fixture before the event day if you possibly can.
Multi-port controllers
On a T8000 or another multi-port controller, one extra thing goes wrong: the export writes data only for the ports configured in software. If the layout was drawn for four ports and you have physically connected six, two of your fixtures will stay dark and everything else will look perfect.
Before exporting, count the ports you are actually using and confirm the layout covers all of them. Then, in the bench test, check that every port produces output — not just the first one. Our controller comparison explains how port allocation works.
Habits that prevent site failures
- Label every card. Write the job name and pixel count on it with a marker. Unlabelled cards get mixed up, and one wrong card at a venue means a fixture playing the wrong show.
- Keep the project file. Store the LED Edit project alongside the card so a change next season takes minutes instead of a rebuild.
- Write two cards for every job. The spare costs almost nothing.
- Format fresh for every job. Never write over an old show — leftover files cause playback faults that are hard to diagnose.
- Back up your project folder. Cards and hard disks both fail. A cloud folder or a second drive protects years of tuned work.
Questions we get asked
Can I copy the files from a working card onto a new card?
Yes, provided the new card is formatted FAT32 and the files land in the root. This is a quick way to produce a spare, though exporting fresh from the project is more reliable.
Can I rename the exported files?
No. The controller looks for specific filenames. Rename them and playback stops.
The card works in one controller but not another.
Different controller models expect different export formats. Re-export with the correct controller model selected in hardware setup.
Can I keep several shows on one card?
It depends on the controller. Some support multiple programs with selection by button; others play only what they find. Check your controller's manual, and test the switching on the bench before relying on it at a venue.
How long does a card last?
Cards wear out with repeated writes, though a controller card is written rarely and read constantly, which is easy duty. Replace a card that has ever behaved oddly rather than trusting it again — they rarely recover.
Card behaviour varies between controller models and firmware versions. If your controller behaves differently, tell us through the contact page and we will update the guide.
Rajkumar
Six years in the pixel LED industry, running a manufacturing and supply business for event decorators and tent professionals across India, and teaching controller programming to working technicians on YouTube.