Toshiba 49L420U does not turn on

Normally on the Panasonic tv this will call for a service call. The key to getting it repaired correctly is to check for a certified Samsung repair shop because most of the parts come from Samsung. Now if you want to do your own research call to 800 number for Panasonic Tv see if there are any problems with that model that the manufacturer has extended but does not post. I had one repaired that the red light on also so I understand and it went out approximately 4 3/4 years. If your in the Atlanta area use Norman electronics they have repaired hundreds on tvs for me due to my work.

dead power board

Blinking of power LED are fault indications. Count the number of blinks occur at one time switch on. For this number, you can get an idea about the faulty section circuit inside it. It will make troubleshooting much narrower. If you wish to get more details about the blinking codes, check this link. Pull up older posts there.

Not sure right off bat, however unplug it from the wall for three or four minutes plug it back in it might reset it?

Hello
The codes for Toshiba TV with Innovage jumbo universal remote control are:
013,049,089,105,
Proceedings

1. Turn on the device that you want to set.

2. Look for the brand name under the specific device listing provided.

(Note: You will notice that some brands will have more than one 3-digit code. During the

code input process, you may have to try more than one 3-digit code that will match your

device brand and model.)

3. Aim the remote control at the device and press down and hold CODE SEARCH button for

at least 3 seconds until the red LED lights up solid red.

4. Press the device button for the item you wish to program, e.g. TV, DVD, VCR, etc. and the

LED light will blink once and then remain solid red.

5. Using the number keys, enter the 1 st set of 3-digit codes from the list. You will notice

that each number that you press, the LED will blink once. After you have entered the

3rd digit, the red LED will turn off indicating that the code was recognized for the device.

(NOTE: If the code entered was not compatible, the red LED will flash several times.

You will then need to repeat Step 3. You have 30 seconds to enter a code.)

6. After the red LED light has turned off. Press the ON/OFF key. If the device you are trying

to program powers off, then you have found the correct code. If the device does not

power off, then you will need to repeat the process again from Step 3, using another

3-digit code.
7. Make a note of the 3-digit code for future use.
OK.

yeah, should stay red when unit is turned off, indicating there's power but it's doing nothing.

Per user manual:
Solid red - power off (standby mode)
blinking red - power off (now cooling)
blinking green - power on (preparing to light lamp)
solid green - power on

Those blinks [flashes] are fault indication (Error Codes). From the number of blinks occur at one time switch ON, you can get an idea about the faulty circuit section inside it. This will make repair easy. These are called blinking codes. Make sure about the exact number of blinking of the standby/power LED, by switching On & OFF the set, for at least two times. Count it carefully. If you wish to get some details, check the site linked here. It has details about blinking codes, and fault locating procedure, to many popular brand TVs and other devices.
http://electro-medical.blogspot.com/
http://homenol.blogspot.com/
http://electronicshelponline.blogspot.com/
If blinks continue without any pause, the main board is faulty.
Search the site by type in the "brand name" to your device, in the "Search box at the top right of the display window of the Homepage" to get gathered related posts.

Is the red light flashing or solid?
If the red light is flashing it is the signal board is bad part number 75001688 $425.00 - $475.00 depending on supplier.

If the red light is solid then you signal cable has come loose or has went bad.

i had to replace the power supply