For your new Echostar DVR, you'll need to get another smartcard from Dish Network, as every set-top box should ideally have its own smartcard. In the meantime, you can try taking a smartcard from an existing receiver and using it in your DVR until you get a smartcard. However, I would not recommend swapping the card between receivers over a long period as this can wear out its contacts.
Unfortunately, I don't have any experience with repairing TVs. If the warranty is up by just a month or two, it's worth arguing with the shop you got it from to see if they would be willing to cover it under warranty one last time, especially with how long it took for the previous parts to come in. Some shops would rather do this than risk the customer not shopping from them again, especially if you've bought other major home electronics or appliances from them. However, if the TV was bought online or the warranty is 3 or more months over, it's very unlikely you will be able to get the shop to still cover it by warranty.