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.
replyEtch it in the top layer of copper, cover it with soldermask. A bit harder to see, but harder to tamper.
replyPut a sticker over it. Sure, the PCB says 2GB, the sticker says 8GB, it was sold as 8GB, how many buyers are going to dig in and really understand what's going on?
replyThat'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
replyThat is in no way trivial.
replyOne 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.
replyThese operations are not hobbyist level, they have access to the machinery to make it trivial.
Please, I could just fill the gap with the same-colored solder mask, flatten it out, cure it, you'd never see the rework.
replyIt is so trivial anyone that's ever done fingernail polish can do it. The process is roughly the same.
No, this is not sufficient, since it would still allow you to swap to shite ram of the same size. This is an age-old problem for counterfeits. The ink on the chip/PCB isn't worth anything. The only way to actually catch this is to do a IQC that runs a full RAM test and hope that if you can't see a difference in performance (throughput, BER, timings, etc), then the chip is correct, with a bit of periodic de-lidding for anything suspicious/sampled. Then, if you can afford it, you blacklist the vendors that are caught changing things.
replyThey also added a bit of internal ink, which is worth just a little more:
> we now also program in some other device attributes, meaning that switching parts of the same size may not work.
Working with vendors in China is entirely adversarial (mostly because their supply chain is vulnerable too), at this scale.
it can be very easily done by burning it with laser on prepared blank box on silkscreen - even iPhones are marked this way with their own serial numbers
replythe only reason why pis are not marked this way is because raspberry didn't wanted to (so far)