In the process of repairing a Colecovision, I've opened my Adam to make some tests to help diagnosing and after socketizing the VDP and scrapping the glue of the cooler I've found this little thingie:

I was expecting a plain TMS9928A, it must be the Texas IC rebranded of course; but the weird thing is that after testing 5 spare TMS9928A I've recently purchased, no one gives me a display, only the original works.

I have two possibilities:

1) It's not a TMS9928A and it's a slightly different chip (it's an NTSC version, I think).
2) All the spare ICs are bad or fake (yes, they come from China...).

Does anyone know more about the Adam VDP or even has replaced it successfully?