Start small board separate from the larger board where does it plug and sit at

Unfortunately, the most likely and common problem has happened; the main power supply has failed.It has probably been marginal for some time but certain components (electrolytic capacitors) don't live forever when used in circuits with fast signals present.
If the power supply is a separate assembly (very common), it is a matter of buying a replacement, removing the old one and installing the new. These are connected with plugs which are not easily interchanged so can be done by a smart layman.
The cost will be between $75 and $150 US for the supply, labor varies depending on area.
If the supply section is on a larger single board, it may be necessary to remove the entire board for repair.
If you can remove the back panel of the set, look for a smaller board with larger-than-average parts on it, There will be large and small cylindrical parts (capacitors) as well as fair-sized blocks (transformers and chokes).This is the section that has failed and should be available from the mfr.'s service center.

In many sets, this is an indication of a failed power supply.

There are at least two supplies in every set; one is active always so the set can receive commands from the remote and requires minimal power and rarely fails.

The other is turned on when the set is to be used and this one, is the likely culprit.

I suggest you contact the service center for your area and inquire about the cost of board repair or replacement. If the latter, keep the failed board since there are small shops (I was one before retirement) with the skills to repair these at a more reasonable cost.

Before opening the back of your set, pull the plug and allow to sit; preferably overnight.

There are nasty voltages inside that you want to avoid.

The main power supply is often on a separate board, will have larger-than-average parts on it, with cylindrical parts (mostly capacitors) and some larger squarish parts (chokes and transformers) and most likely a 'heat sink,' a finned aluminum structure with parts attached to it.

Look for a tag with a part number on it and have this available when you start looking for service or new board.

These assemblies are nearly always only plugged into the rest of the set with clearly dissimilar plugs so incorrect connections are somewhat prevented.

If you are unsure of yourself, take several pictures of this area before disconnecting anything that you can then refer to if uncertain.

Remember, many assemblers of most of these just recently came in from small farming villages in Asia so assembly is kept simple.

Good luck-

clean carb

The compressor relay is bad on the main control board . Unplug the refrig and pull the refrig out and remove the 8X10 small panel on the back . You will see a blue plug with 3 larger (120v) wires going to it . Remove this plug . Looking at the plug , you will see : wire1 , wire2 , space , wire3 . (this is on the plug NOT the board ) . Using a short piece of insulated wire , with about 1/4" stripped off both ends , insert 1 end into wire1 and the other into wire3 . Plug the refrig back in . This will start the compressor to verify the main control board is bad . Pt # WR55X10942 .

The compressor relay is bad on the main control board . Unplug the refrig and pull the refrig out and remove the 8X10 small panel on the back . You will see a blue plug with 3 larger (120v) wires going to it . Remove this plug . Looking at the plug , you will see : wire1 , wire2 , space , wire3 . (this is on the plug NOT the board ) . Using a short piece of insulated wire , with about 1/4" stripped off both ends , insert 1 end into wire1 and the other into wire3 . Plug the refrig back in . This will start the compressor to verify the main control board is bad . Pt # WR55X10942 .

The power light is using the same small 'always on' power supply that keeps the infra-red receiver for remote functions alive too. It is likely that the main power supply is sick and will need repair or replacement.
This is probably a separate board (these are often outsourced to specialty companies) and should be user replaceable once you identify it.
What you can do is; unplug the set, let it stand overnight or at least several hours, remove the back panel and look for a separate board with mostly larger components on it; it will have a ferrite core (no laminations as with a line-frequency part) transformer on it and several larger capacitors which are cylindrical and mounted vertically to the board.

Before touching anything inside, especially on that board, allow several hours to be safe since the larger capacitors can hold a painful voltage charge for some hours.

If you see signs of overheating such as discoloration of the board material, the PSU may not be repairable but if you can find a part number on the board, you might be able to buy the power supply from the mfr.(or company linked below) and install it yourself but it will likely have the same problem eventually unless they have altered the design or improved component quality.
If there are no signs of heat damage to the board, there may be companies offering to repair it as a subassembly instead of repairing the whole set which could be much more expensive.
If you choose to replace or have it done, the main power supply still may not be at fault since most are capable of switching on and off if a downstream problem is causing an overload and the power supply for the backlight may be at fault.

Possible board source:

Jimmy's Parts

If the cooling fan is running, the main power supply is sending you a message; it will eventually die and not come back. Check for fan operation first, then, if it is running, pull the AC plug overnight, remove the lower access panel and look for a separate board visibly related to the AC line coming in. This board will have larger components on it, some cyllindrical some block-like.
If you can find the assembly number (often on a label) record it, if not, then your exact model number, call the mfr. and ask about repair or replacement cost.
If you have to buy a new board, don't pitch out the old one but look for an independent repair company offering power supply repair. The repair cost may not be much lower than a new board but if you have one on hand, you won't miss much TV while swapping out the 2nd failed supply.

Your good description of events is helpful and points to the power supply as the culprit. This is probably on a separate board (they are often out-sourced) and may be easy to replace. You should be able to identify the board since it will be smaller than the main board and have larger components on it including one or more transformers and larger capacitors (plastic shrink-wrapped cans of different sizes). 
If you want some confidence before rushing out to buy one or have this one repaired, you could pick up a can of 'freeze spray' from any electronics supplier (Radio Shack may have it too), pull your set from the wall, loosen the screws on the access panel behind (don't remove it; that may improve cooling and mask the failure), keep the freeze spray handy so if it fails, you can pull the panel and start spraying the PS board. I'd start with the small to medium sized capacitors since these are often at fault once aged.
Good luck-

Your description of events is helpful and points to the power supply as the culprit.  This is probably on a separate board (they are often out-sourced) and may be easy to replace.  You should be able to identify the board since it will be smaller than the main board and have larger components on it including one or more transformers and larger capacitors (plastic shrink-wrapped cans of different sizes).  

If you want some confidence before rushing out to buy one or have this one repaired, you could pick up a can of 'freeze spray' from any electronics supplier (Radio Shack may have it too), pull your set from the wall, loosen the screws on the access panel behind (don't remove it; that may improve cooling and temporarily mask the failure), keep the freeze spray handy so if it fails, you can pull the panel and start spraying the PS board. I'd start with the small to medium sized capacitors since these are often at fault once aged. 
Good luck-

Hey Ed,

I hope I can help, It doesn't open from the back, it opens from the front.... carefully! There are four support screws, which hold the LCD screen to the desk stand,after removing all the support screws (4) on the back under the support stand cover.(which pull up to remove) (Remember! the whole case and face frame is plastic, so take your time). Work to separate the black face frame around the LCD from the silver case. Its held together by small plastic clips on the face frame to the wall on the LCD case. Start at one of the corners and slowly pry the face frame and silver case apart. (separate it inch by inch, work your way around the case carefully. If one corner doesn't give, go to another side.
Putting back together works reverse, the face frame and the case snap back together, Carefully! And replace screws (4).

Russell

P.S. I have three LCD models from Westinghouse, LCM-22w2, L2210NW and the L1916HW. They all open the same way.