Cannot power on

replace the power supply on the plasma TV

Sounds like your power supply capacitors have failed. Google for Z1234TV and see if you can locate a power supply capacitor repair kit for your model.

If the system is connected properly and the main tuner power is on you will see the orange standby light on in the front of the main diamond shaped control unit. If that light is not on, you have not connected the system and power cables properly.

If the standby light is not lit, press the power on/off button in the middle of the rectangular processor/tuner to turn it off and unplug the main power cord from the main tuner/processor from the wall. Next, ensure that all of the power, video and audio cables from the diamond shaped control unit are properly connected to the large tuner/processor. Since you are there, check any other av in/out connections.

Now that you have checked and adjusted the cables between the controller and the tuner, plug the tuner back into the wall and push the power on button. Now check the standby light again on the diamond shaped controller unit.

Once that light is lit, press the silver, horizontal on button in the middle of the diamond shaped display unit, or the Power Standby/On button on your main remote control and you are operational.

No standby light up front= Main Board. Standby light lit but wont power up = Power supply board.

you can unplug the power cord and drench the power and after go ahead and plug in back the TV and try to start it

If you have a power cut when tv is on - it shuts down for safety - leave it for 1 hr or overnight - then it works!! I have a UPS as our power here in Mozambique always goes out

Here's an excerpt from the Sony Manual online. And the link - http://esupport.sony.com/US/perl/webtree.pl?template=EN&mdl=KDF55XS955&content_id=68&category_id=11&problem_id=52

The POWER/STANDBY (red) indicator flashes three times
If your power/standby indicator is flashing in a pattern of three flashes, this may indicates that the lamp cover is not attached securely. Follow the directions in the Operating Manual under changing your lamp that related to closing and securing the Lamp Cover. Ensure that the Lamp Cover Door is securely fastened by tightening each screw.

The POWER/STANDBY (red) indicator flashes continously
If your power/standby indicator is flashing continuously, and the lamp cover has been secured, your TV may be in need of service.

The POWER/STANDBY indicator is lit up green (not flashing)
A sustained green light indicates your TV is on.

The POWER/STANDBY indicator is lit up red (not flashing)
A sustained red light from your power/standby indicator simply indicates that your TV is in standby mode. This shows you that your TV is ready to be turned on with the remote.

Is it the power light and not the lamp light? If the lamp light is flashing then replace the lamp.

When you push Power Button on remote, TV goes to Standby state i.e its power light (LED) lit but no picture / no sound. Power button on remote has symbol looks like.. ( ! )

hi, i have read somewhere that you need to replace both 100u / 25 caps aswell.
the info came from a user on here called PaleFace but i cannot find the original post now and i have the same problem with my tv.