If the police do not believe this is a criminal matter you need to look up the small claims court in your county. They handle civil matters for items worth less than $7,500. The court has a useful guide which I added to help you understand the forms and attempt a filing. This court can give you an order that will help you get your TV back.
These statements do not constitute legal advice. They are meant to be general in nature, for any specific legal questions you should always seek the counsel of an experienced attorney.
In small claims court you can seek a judgment for the value of the television which is probably sufficient. If the actual TV (or other possessions) are more important than the value then you need to go to county court and file a replevin action to get an order requiring the turnover of the property.
You can reach Harkess & Salter LLC at (303) 531-5380 or info@Harkess-Salter.com. Stephen Harkess is an attorney licensed in the state and federal courts of Colorado. This answer is for general information only and does not create an attorney client relationship between Stephen Harkess or Harkess & Salter LLC and any person. You should schedule a consultation with an attorney to discuss the specifics of your legal issues.
I agree that this is a small claims court matter. However, here is one more path to resolution with a slight twist. You can go online to submit your case to the famous Judge Judy TV show. It is my understanding from one of my own clients who did this successfully that If the show accepts your case, they will pay travel and accommodation expenses for you and the defendant (ex-boyfriend) to travel to do the show and pay plaintiff's damages (your losses). In that way, you would not have the typically problematic practical issue of actually collecting a money judgment from your presumably uncooperative ex-boyfriend if you win in small claims court. Good luck.