Intel 5350 Wimax Intel says is Illegal to install unless came with system.

[Aluminum]

FYI intel and many other OEMs are snowjobbing you, they ought to be careful about claiming matters of law as well.

If you start causing signal problems or (here is the only thing to actually think about) you resell the system to the wrong people is the only way the FCC would ever care. Until you interfere with something, nobody is running around with frequency counters and these things are so underpowered it would be a miracle if your laptop doesn't have proper shielding regardless.

However, beware that on ebay most if not all the cards for sale now are remarked engineering samples! The legit ones ran out months ago, the "generic" version of the card is not being made anymore.

While the hardware is likely just perfect the wimax certificates will not be considered "valid" by most ISPs...they're not "paid for" so to speak. These don't use wifi-style encrpytion, they have their own whitelist of certificates hence all the certification thats paid for. Thats assuming you can work around duplicate/dummy wimax adapter MAC address problem in the first place.

The wifi chips onboard are identical to retail 5300s and I've not seen any MAC problems there, multiple cards from the same source all have different valid intel range MACs. ES usually isn't an issue with lots of hardware and people have been selling it on the grey market forever (unless its just plain broken, or remarked to something fake) but this is one of those cases you will be straight up burned.

FWIW I use multiple legit and ES 5350s in desktops and laptops, they are very good cards. The wimax hardware in the ES versions DOES work, but I have access to some test networks running in prerelease area that are not configured like the launched ones will be. (you can also run your own if you really want, there have been some corp wimax bands around)
I've yet to try more than one of the ES at the same time either.

OP, yes you are running into the "this slot is not a fully wired minicard slot" issue. Many laptops that have 2 slots are actually splitting 1 physical slot into a pcie_x1 only and usb only slot, some larger laptops with 3 slots are only giving you 1 full slot and another two "half" slots.

Many dells I've run into do the latter. The fully wired slot is usually the WPAN, the WLAN is pcie_x1 only and the WWAN is usb only. Its rarely a problem because thats how nearly all wifi and broadband cards are made, the WPAN acts as a catchall for outlier configurations.

PS, intel will also generally ignore you if you try to confirm product validity...so much for the old days when if you told them you think you might have a remarked cpu they would phone you up and be your new best friend pumping for details.