Add WWAN Card and Antennae

Lenovo publishes their service manuals anyway, you just need to find the manuals and parts.

Not sure if this is your T490, but have a look to have some idea what they publish anyway.

https://download.lenovo.com/pccbbs/mobil...

I have a T480 with same issue along with the P53s missing the WWAN antennas. The P53s had a damaged Display and I ordered by part number an exact replacement on eBay for 22 bucks plus S&H. While I had the lid apart I had the antenna kits shipped in. It was a two week long project just waiting for the parts. Lots of patients went into feeding the antenna wires down the sides of the display and getting them past the HINGES was a chore to keep them from getting pinched. The Fibrocom Cards have IMEI numbers on them and it's important to keep the "Stickers" handy as the Barcode is necessary for a cellphone retailer to sign you up for a SIM Card. I chose Boostmobile (Black Card AT&T) over the AT&T only because the DATA Caps at 22Gigs a month where as Boostmobile is suppose to throttle down past 30Gigs a month. AT&T does cap but Boostmobile didn't seem to show any slowing down past 50Gigs a month. AT&T charges $20/mo plus dumb taxes totaling me $27+. However, Boostmobile has a $25/mo totaling $26.67 with taxes and fees. The trick is setting up the APN for internet access with Boostmobile by deleting the APNs AFTER inserting the SIM Card and creating a new APN: 1st line is "Boost" and 2nd line is "ereseller" with the rest of the fields empty. Reboot the laptop twice - slowly, and let the machine do the work for you. What you are looking for is the Signal Strength Bars in the lower right corner. When I have the Bars, I have internet access. It's a wonderful feeling of freedom not being tethered to someone's Wi-Fi and safer, too.

By the way< AT&T requires you to have a $70 cellphone service with them in order to get the $20 Data only SIM Card. Otherwise, you'll be paying $70 plus taxes and fees just to have your laptop with Internet Access. Boostmoble only requires AutoPay to get the $25/mo plus tax. Just remember to create a new APN to get the Boostmoble to provide Internet Access. The ereseller has to be spelled exactly as shown here. No capital letters. Have fun!