Fake Chips and What’s Inside Them

[exxos]

[tOriman]

Hi,

This is common. If you see on the "old" chip lettering not made with paint but laser engraved in light brown like on this video - it could be a fake or "repainted". Next hint - all sold chips have same date code :) You can try some acetone on "paintings" too. The final examination should always be done under a good microscope after decapsulation.

tOri

[stephen_usher]

The trouble is the Chinese suppliers seem to love relabelling the chips, even if they're genuine, for some bizarre reason. So, just seeing them relabelled means nothing these days.

[rubber_jonnie]

Saw a video on Curious Marc's channel a while back about heat decapping.

As @stephen_usher said though, sometimes relabelled chips are actually genuine, the vendors just decided to clean and re-label for vanity purposes, so it is harder to ID bad chips these days.

[Sbn31]

Hi, recently i ordered 10 multiplexer 74F257 ships on ali, they were all fake. They refund me easily but then I thought I was enough lucky that these ships didn't destroy my atari with some short circuits or wrong connexions.
So maybe to avoid destroying any device these fake ships are just made of metal pin inserted in plastic with nothing more.(sorry for my average english)

Screenshot_20260210-110248_AliExpress.jpg

[rubber_jonnie]

Hi, recently i ordered 10 multiplexer 74F257 ships on ali, they were all fake. They refund me easily but then I thought I was enough lucky that these ships didn't destroy my atari with some short circuits or wrong connexions.
So maybe to avoid destroying any device these fake ships are just made of metal pin inserted in plastic with nothing more.(sorry for my average english)

Often they are just ICs that are something else entirely but happen to have a common number of pins, so they relabel them so they are something more saleable.

Where did they come from BTW?

[exxos]

Yeah never ever order parts from China unless you have absolutely no choice to take the gamble..

I purchased things like GAL chips, got 100, they seemed totally blank.. as in , no resistance whatsoever between any of the pins. There were just basically like a "shell" and no actual silicon inside them at all from what I could detect.. I could write a book on all the stuff.

Like I said before, buying things like the 030 CPUs, China used prices are not much cheaper than buying genuine NOS these days.

[rubber_jonnie]

Yeah never ever order parts from China unless you have absolutely no choice to take the gamble..

When I was building my OSI 600D I bought RAM from Ali Express and aside from some DOA ICs I did pretty well. Someone else did the same from a different Ali Express supplier and had a terrible time with fails which could have been fakes for sure.

Your mileage may vary...