I have no picture on my sony KDF-50WE655

Check the site www.TvRepairKits.com for a blinking green light fix. There are two parts that fail in this set. This is fairly common.

Make sure that lamp cover is fixed back on its position securely after lamp replacement, turn On tv to check.
If still no picture or sound then check power/standby light is blinking?
If yes, count it how many times it blinks after 3 seconds long pause and let me know to diagnose possible cause of problem.
Thanks.

Hi,
If you see standby red light blinking on Tv front with 3 seconds interval then count its blinks from pause to pause and let me know, its an error code.
And if TV does not even show standby light then check fuse in power supply that would be blew off for some reason, replace it.
Still problem? let me know with exact model number of your Sony TV.
Thanks.

Lamp XL2200u Call FOX 1-800-227-5369

3 times blink means Lamp Cover is not placed back that was removed while replacing lamp, make sure lamp cover is fixed securely in its position.
Thanks.

check the bulb door and make sure its closed all the way. be sure the bulb is firmly pushed into its socket. if the problem is still there you may need to repair the power supply board.

4 times blink error shows that any FAN is not running in TV as there are 4 fans in this TV.
Please check fan connectors and make sure all are plugged securely.

4 blinks shows problem either one or all 4 fans are not working AND internal temperature high error.

If you are familiar with TV repair and know basic electronics then unplug TV from AC outlet an take off back cover and check fans are running?

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://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, [Exclude the model number] in the "Search box at the top right of the display window of the Homepage" to get gathered related posts.

you have defective power supply! at the hot side section!