Can I turn on a Toshiba 32L4200U without the remote?

Chances are you have defective backlights, have you tried the flashlight test?

Buy a universal remote control and program it to work with the television and DVD player you have.

which of these TVs is yours?

Originally supplied with models: 19AV600U, 19C100U, 19SL400U, 22AV500U, 22AV600U, 22C100U, 22SL400U, 26AV500U, 26AV502R, 26AV502R/U, 26AV502RZ, 26AV502U, 26AV52R, 26AV52U, 26C100U, 26C100U1, 26c1100u, 26SL400U, 32AV500U, 32AV502R, 32AV502RZ, 32AV502U, 32AV50SU, 32AV52R, 32C100U, 32C100U1, 32C100U2, 32CV510, 32CV510U, 32DT1U, 32E200U, 32RV530U, 32SL400U, 37AV500E, 37av500u, 37AV502R, 37AV502U, 37AV52R, 37AV52U, 37CV510, 37CV510U, 37E200U, 37RV525R, 37RV525RZ, 37RV52R, 37RV530U, 40E200U, 40E200U1, 40E200U2, 40FT1U, 40G300U, 40G30U, 40RV525R, 40RV525U, 40RV52R, 40RV52U, 40XF550U, 40XV640U, 40XV645U, 40XV648U, 42AV500U, 42RV530, 42RV530U, 42RV535U, 46/40/55S41U, 46G300U, 46G30U, 46RV525R, 46RV525U, 46RV530U, 46RV535U, 46RV53CU, 46SL412U, 46XF550U, 46XV640U, 46XV645U, 46XV648U, 52RV, 52RV530U, 52RV535U, 52RV53U, 52XF550U, 52XV645U, 52XV648U, 55G300U, 55HT1U, 55S41U, 55SL412U, 19AV600UZ, 19SL410U, 24SL410U, 32C110UM, 32FT2U, 32SL415UM, 40E210U, 40SL412U, 55G310U, 42RV525R, 32C100UM, 32DT2U, 40E210U1, 65HT2U, 32RV525RZ, 46RV525RM, 40G300U3, 46G300U1, 32C120U, CT90302 Programming Instructions and Codes, CT90302, 75022871, 75017678, 32E20U, 37E20U, 40E20U, CT90325, 75028874, 24SL410UM, 32C110U, 32SL410U, 32SL410UM, 40E210UM, 46G310U, 32C110U1, 32DT2U1, 40FT2U, 32C10U, 19L4200U, 24L4200U, 32L4200U, 40L5200U, 46L5200U, 50L5200U, 26C100UM, 40E200UM, 55HT1, 50L2200U, 39L1350UC

Use the manual on off button the set has.

Since most passwords require a number sequence to be entered I doubt it can be done without the original remote and the correct code numbers.

You just have leave it u know u just to let somethings go

This may not be possible; it may be designed to prevent children from operating the set without an adult with the remote present.
You can probably buy an original remote or a known substitute from:
Remotes.com

Unfortunately, many models are now without menu buttons. You will probably want to go to the Toshiba website and request a replacement remote, or try to find a remote that will work with all toshiba models.I don't recommend a universal one, only because they can sometimes be junk, if they are intended to control many different kinds of devices. You may want to try a single-device universal remote instead.

Depending on the universal remote you can usually program the remote without knowing the codes. One way is to turn on the television, then follow the basic programming instructions for the remote, but instead of entering a code, hit the power button over and over again until the television turns off.
I hope this helps.
Ken