I have a Sony kf-50we620, It started having problems this week. Sometimes, not always, I turn it on, the green light flashes and the TV will eventually start but it takes over 2 minutes to start. I will get a picture for a second, it goes away and will come back. Sometimes it wont turn on at all and the red light will flash 4 times. Other times the "lamp" light will flash. Any help will be greatly appriciated

it could be the lamp but it might also be what is called the color wheel.. have you checked the lamp .,, have you removed and physically looked at the lamp. also does the light blink after shutdown.

possible defective lamp. The lamp part number is XL2100u

The light engine is going out. Contact Sony. They have been replacing some of these.

Replace your Lamp.

Your owner's manual for the television will contain a troubleshooting section that will describe the blinking codes for the various lights, and what they mean.
However, in your case, it probably means the light is burned out.
The bulb on my TV tends to burn out about every 16 months (I watch TV for many hours per day, so your experience may be different). If your TV is still under warranty, I would suggest you contact the store where it was purchased, or contact the manufacturer.

5 blinks code shows problem with Lamp Drive circuit (ballast supply) and / or Lamp itself.
How old is this TV and have you replaced lamp before?

It is symptom of weak Lamp in your TV, replace Lamp with following part number..
A1606034B LAMP BLOCK XL-2100U
It is available in Sony Accessories for $200
Always buy Sony Original Lamp for your Sony TV and avoid aftermarket/ cheap lamps.

Replace lamp.

5 flashes indicates ballast malfunction. 4 flashes indicates fan not working. I would replace the big fan in the back because it is a common failure for this model. But befor this check to see if the lamp door is warped from overheating. If it is the wiring on the balast good be burnt and the light engine could be damaged.

my front panel sound is not working.......?
how i can do this.?