How do I make my husbands smart phone "appear" to be broken / not working?

[AC Question]

I bought my husband a new smartphone with T-Mobile and switched our 3 phones over to T-Mobile from Sprint. He's nervous to use his new and BETTER phone and keeps putting off switching his line. He has an old Evo 4g. He keeps saying he'll switch it when he has time to learn the new phone. Now 4 months have gone by and I'm paying for the new service on T-Mobile and me and my son are using the new T-Mobile but I've had to maintain one line on Sprint to appease him. If his old Evo appears to be broken, he'll have no choice but to switch over. It's deceptive but I'm out of options. I don't want to lose the VM or stuff he has on his Evo of course, just want to nudge him out of the past and the old phone and into the present day. Any suggestions?