I have a Panasonic Plasma TV model TC-P55ST30 with no picture display. I replaced the main board and when I press power I get a red indicator light but no picture what should I do next?

These 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://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.

These 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://electronicshelponline.blogspot.com/
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.

Check and replace damaged component/s at its back-light inverter board, or replace this board as card basis. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts. It will be best to replace the inverter board as card basis.
http://electronicshelponline.blogspot.com/
To some model sets; especially LED back-lighted types; the back-light inverter circuit will be part of the main power supply board [SMPS]. In such cases, the power supply board might need replacement.

These blinks are fault indication, and known as blinking codes.From the number of blinks occur at one time switch ON; you can get an idea about the faulty circuit stage inside the TV.This will make repair easy. For more information, check the link

Main digital board should be troubleshooted. If you are not familiar with electronics, do not attempt to repair. Whether you suffer fatal electrical shock! Instead, contact any experienced service technician, or the nearest service center

I had a similar problem with my Hisense TV and I replaced the "Main Board". Got the part on ebay. Don't know if this will help.

Good luck!

If it is from ShopJimmy you can't be certain it's a good one :-)

And second, that sounds like a main board problem, not power board problem.

10 blinks for this tv is not always an A Board issue. It can be a problem with the power board as well. A technician should look at the set to dertermine where the problem lies otherwise it is just a guessing game of inni minni miny moe.

Tries unplug,replug the tv back like an hour later.The tv now,should resetting itself back to the factory setting.The tv should work now.Not,than the tv power supply board have problems,not giving the tv it wright voltages anymore.The tv power supply board that the board,where the power a/c cord plug into it.Tries websites like Shopjimmy.com,Ebay.com to buy a whole refurbish power supply board for the replacement.

power board or screen