Buying a used DMA card: a checklist
A used board can be a good purchase. But only if you price the hardware alone and get the photographs before the money moves.
By Lethal Hardware Desk
Buying used is a reasonable way into this, but it is also where people lose money for reasons that were visible in the listing. The board is the part with resale value, almost everything else is worth less than the seller believes, and the firmware already on it is worth least of all. This is the checklist we hand people who ask, in the order it is useful.
What to inspect
| Part | What you are looking for | What a bad answer looks like |
|---|---|---|
| PCIe fingers | Even, unscratched contacts with no bent or missing teeth | Gouges, discoloured contacts, or one finger visibly shorter than its neighbours |
| USB-C sockets | Both sockets straight and firmly attached, with no play when a cable is inserted | A socket that rocks, sits at an angle, or has lifted from its pads |
| FPGA marking | The part number readable on the chip itself | Sanded, painted or obscured markings — or a refusal to photograph it |
| Silkscreen | A model name and a revision printed on the PCB | A listing that only repeats an FPGA class such as 75T |
| Rework | Factory-looking solder throughout | Flux residue, fresh solder around the FPGA or sockets, lifted pads, scorch marks |
| Flash chip | Present, unswollen, not obviously replaced | A missing or visibly reworked flash chip beside the FPGA |
| Bracket | Present and straight, with the screw hole intact | A missing bracket, which is a fitting problem rather than a cosmetic one |
The sockets and the fingers are the wear items. Everything else on this list either works or is obviously wrong in a photograph.
The photographs to ask for
- Both sides of the board, flat on, in focus, uncropped
- A close-up of the FPGA marking, readable at full size
- A close-up of the silkscreen model and revision
- Both USB-C sockets straight on, close enough to see the housings
- The PCIe fingers edge-on, along their length
- The card seated in a machine with its LEDs lit, in the same session as the rest
The last one matters more than it looks. Any single photograph can come from a search. A set taken in one sitting, showing the same board from several angles and powered in a slot, is far harder to assemble from somebody else's pictures. And if the seller will not photograph the silkscreen, you have your answer, and it cost you nothing to get.
What a silkscreen revision actually tells you
It tells you which board this is, which is not the same question as which FPGA it carries. Firmware has to drive the USB bridges and the flash chip that are physically present, and two boards that both say 75T on a listing can differ in PCB revision, bridge and flash part. The class label describes the logic capacity of the chip and says nothing about the layout around it. When you order firmware, the revision is one of the inputs that decides whether the image will work at all, which is why it gets photographed rather than described.
An image built for somebody else's card was generated against that FPGA's DNA ID and will keep configuring that chip. A seller can honestly say it works, and it is still worth nothing to you. You inherit a file nobody will support, bound to a value you cannot request rebuilds against and carrying whatever history that profile already has. Price the board alone, and assume you are buying a new image.
Sellers to walk away from
- Stock photographs only, or images that turn up elsewhere in a search
- A refusal to photograph the FPGA marking or the silkscreen revision
- Firmware presented as part of the value, especially with a price attached to it
- A claim that the installed image transfers, is licensed to you, or will be supported by whoever built it
- Pressure to settle payment before any specific photograph exists
- Any description of a board as clean, safe or undetected, which is a claim about firmware and behaviour rather than about hardware
None of that requires assuming bad faith. A seller may genuinely not know what a DNA ID is and, in perfectly good faith, still sell you firmware that is useless to you. The checks are identical either way, which is convenient, because you cannot tell the two apart from a listing.
After it arrives
- 1Seat the card in a powered-down machine and screw the bracket down
- 2Cold-boot the game PC and confirm the card is enumerated before installing anything
- 3Connect the second PC to the data port with a known-good USB 3 cable
- 4Read the DNA ID off the chip yourself, and keep it with your records
- 5Only then order firmware, quoting that DNA, the silkscreen revision and the FPGA marking
An afternoon of photographs and one cold boot is the whole cost of doing this properly. Set against a board with a rocking USB socket, or a revision nobody publishes images for, the checks are the cheapest part of the purchase.
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