Thread

Raspberry Pi blocks changing RAM chips

258 points · 211 comments · edandersen

Aurornis · 1789997234 · focus · HN ↗
There were sellers buying the smallest RAM units, changing the RAM chips, and then reselling them as the higher RAM SKUs. The sellers who do this don’t always care to use good RAM chips and may even use QA reject parts. When the unit doesn’t work correctly, the anger and RMA requests are directed back at the Raspberry Pi foundation.
1. Tepix · 1789999274 · focus · HN ↗
  The user friendly option would be to print the amount of RAM in very large letters on the PCB. There happens to be a lot of suitable surface on the PCB to the right of the text "Raspberry Pi 5" on the PCB anyway (§). Right now the amount of RAM is hard to read and easy to modify (move a little tiny SMD resistor).
  Drawback: You need different silkscreens for different amounts of RAM.
  Btw, if you're worried about RAM-swapped units you can already verify them as described at <a href="https://geekworm.com/blogs/news/prevent-ram-swapped-raspberry-pi-5-how-to-verify-factory-ram-size" rel="nofollow">https://geekworm.com/blogs/news/prevent-ram-swapped-raspberr...
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  (§) as can be seen here <a href="https://pip-assets.raspberrypi.com/categories/1129-pcn/documents/RP-006041-PC-2-PCN%20Raspberry%20Pi%205B%20Rev%204.pdf" rel="nofollow">https://pip-assets.raspberrypi.com/categories/1129-pcn/docum...
  1. buildsjets · 1790010382 · focus · HN ↗
    A little bit of acetone and a q-tip will remove the silkscreen, and then the PCB can easily re-marked by the scammer. Having a new silkscreen made is pocket change.
    jackyinger · 1790010507 · focus · HN ↗
    Etch it in the top layer of copper, cover it with soldermask. A bit harder to see, but harder to tamper.
    hasperdi · 1790014973 · focus · HN ↗
    That's still trivial to defeat. They're very capable and determined. In the olden days they used to mill the top of microprocessor ie intel x86 to remove the engraving and engrave the fake label. These days I imagine it's way more advanced
    unrented7977 · 1790016403 · focus · HN ↗
    That is in no way trivial.
    hasperdi · 1790020400 · focus · HN ↗
    One way of doing it... You can blast away the original markings / copper using laser and put something in place like sheet of copper or something that resembles copper, add solder mask layer on top. Done.
    These operations are not hobbyist level, they have access to the machinery to make it trivial.
    lightedman · 1790024433 · focus · HN ↗
    Please, I could just fill the gap with the same-colored solder mask, flatten it out, cure it, you'd never see the rework.
    It is so trivial anyone that's ever done fingernail polish can do it. The process is roughly the same.

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