How can you turn on the Magnavox tb110mw9 analog to digital converter box if the remote has been lost?

Daphne, Try using auto code search feature, found on most universal remotes. Instructions should be in your manual. From one of the forums they suggested this. Place your tv on channel 3.
Point your GE universal remote at the converter box, press and hold the setup button until the red light remains lit, then press and release the DVR/AUX button. The red light will blink once.
Enter 0581 as the code, then press Power and the Converter box will turn on and your channels will pop right up.
Check the attached links,instruction,guides, read through them, as they have fixes to program remote. Good luck
"I hope this helped you out, if so let me know by pressing the helpful button. Check out some of my other posts if you need more tips and info."

RC Controlling the Magnavox TB100MW9 Digital Analog Converter Page 2 of 2
https://answers.yahoo.com/question/index?qid=20130917205010AAu9Gpg
Remote Code Finder

To be honest I never got a universal remote to work Magnavox TB110MW9 DTV Digital to Analog Converter

I googled, found this: http://www.dtvhdantennas.com/universal-replacement-remote-control-for-magnavox-tb110mw9-digital-converter-box/
So if this is your universal remote, it should have codes in the instructions. OR try this it might have an answer for you.
http://www.fixya.com/tags/magnavox_tb110mw9_remote_code

OR: http://tv.manualsonline.com/support/magnavox/tv-converter-
http://www.dtvusaforum.com/converter-boxes-atsc-tuners/16614-anyone-have-magnavox-remote-code.html
Has some actual experience and possible codes. One says RCA universal has code.

If you wish to get more details; check the sites linked here. It has set-up code list & set-up procedure to many popular brand remote controls. Common codes to check devices with different brand TVs are given, in the order of the device's brand name list in alphabetical order. Pull up older posts. Surf the site with patience.
http://remotesearch.blogspot.com/
http://electrohelponline.blogspot.com/

This is not a remote control problem. Check its main board.

No. it need a remote control to operate.

sounds like you have a faulty box. or no power going to it. If the power button on the unit isn't turning it on or off then its your unit. if button on your unit is working then you will need a new remote. To purchase a new one try Replacement Remotes.