No power System does`nt work at all,I plug it to the wall outlet turned it on, standby light don`t turn on, checked both fuses and are ok. What seems to be the problem?

Plug the power cord directly into a wall power outlet, and make sure that the standby light is lit (turn it on/off manually to see if anything changes). If there isn't any light, then it's most likely broken.
If the TV works again, being plugged into the power outlet in the wall, then the problem is with the cable box (i bet you figured that out too).

I don't know about the newer receivers but this sounds like an arching OFF/ON power switch that was a problem on Pioneer receivers years ago. I would bypass the switch and see what happens.

1. Unplug unit from wall.
2. Jumper two wires going to off/on switch using alligator clip with insulated boots on clips.
3. Plug amplifier into disconnected circuit breaker/fuse protected AC strip.
4. Plug AC strip into wall outlet, turn AC strip switch ON and see if problem disappears.

If you're talking about a powered subwoofer pluged into an electrical wall outlet check the wall outlet. One of my kids could not get a lamp to turn on in the den. It turned out the outlet was switched off from accross the room by a wall light switch. To check your electric wall outlet, plug in something, like a lamp, fan or a clock and see if it turns on. If not, look for wall light switches and flip them on and off. If it (example fan) dosn't turn on, you have a problem with your house electrical system. Probably right there at that outlet.

i know these suggestion might sound sometimes stupid and irrational but best to start from the beginning. you use the remote to turn the tv off or turn it off at the wall whilst switched on?
is there a standby light on the tv (usually indicated red)? if this is on its a good sign at least we know the tv is getting power.
is there a standby button on the tv? has this been switched off?
if these fail and you have changed the fuse as you said then it would seem that the tv power unit has burned out and may be time to pull the guarantee out or bring to the local repair shop.
hope this helps

Not intended to offend;
1. If using A/C (house electrical power), please check if electrical wall outlet is active. Attempt to plug-in another electrical device such as a lamp, clock, radio, etc.. If the electrical wall outlet has top and bottom plugs, try the top and then the bottom plug to see which one works. Sometimes, the top outlet will not work, yet the bottom outlet does work. The wall outlet should be replaced by qualified technician.
2. If both outlets do NOT work, and the outlet is GFCI breaker protected, maybe pressing the RESET switch on the outlet will power-up the outlet.
3. If the outlet is NOT GFCI breaker protected, check your electrical fuse box for a tripped fuse. Sometimes, a tripped fuse is NOT visible. May have to trip the specific fuse or all fuses to off, then back on. Recheck the wall outlet.
4. Once your know the outlet is live, check the power cord (a/c adapter for laptops) to make sure they are securely plugged-in to both the wall outlet AND the PC or Laptop.

Will need more information once the above steps are taken:

Is it a Desktop or Laptop?
Make and Model (if known)?
Any lights (glowing) on the desktop or laptop?
Any lights on the A/C adapter if its a laptop?

hi,
check the power cable first. also the power at the wall out lets.
if ok the you have to check the input ac fuse of your receiver. your recever has problem with its power supply stage, that's why there is no standby light also. fist of all check the fuse. then check the standby transformer is it faulty or not. the system will power up if the standby transformer is ok. standby transformer is a small transformer near the mains transformer. check these things first, if u need any further assistance feel free to contact me through fixya.
ok

Try connecting the TV directly to a different wall outlet and check. If the issue persists, try power resetting the TV. Turn Off the TV and remove the power plug from the wall outlet for 1 minute and reconnect it and check the operation. If the issue persists, then the TV requires service.

Try plugging into another known good wall outlet. if still not standby light then the power board needs replaced.

If TV is completely dead, no green/orange light, no any clicking sounds after you unplug it from the wall outlet and plug it back in - it is a problem with Power Board. Best case scenario - It's just a fuse that needed to be replaced. You have to remove back cover and locate fuses (1-4) on the board that power cord is attached to. You have to use multimeter to check it. If fuses are OK - next step is to replace whole power board. But before you do anything - make sure you got power out of the wall outlet and/or your power strip is in working condition.

COULD BE FANS NOT WORKING. TAKE BACK OFF AND SEE IF TURNING, CLEAN THEM, OR TURN STAND BY MODE OFF OR GO TO SONY.COM, TROUBLESHOOTING OR The STANDBY light is flashing on the television and there is no picture or sound. Solution
The STANDBY light will flash if an issue is detected within the television. This can sometimes be resolved by simply following the steps below to reset the television.

1. Turn off the television. IMPORTANT: For a projection television that uses an internal lamp, wait 5 minutes after turning off the television to allow the lamp to cool before continuing with the following steps.
   
2. Unplug the television power cord from the electrical outlet.
3. Let the television remain without power for 60 seconds.
4. Plug the power cord back into the electrical outlet. NOTE: If the television is plugged into a power strip or surge protector, remove it from the power strip or surge protector and plug it directly into the wall outlet. If the issue is resolved, the problem is with the power strip or surge protector and not the television.
   
5. Turn on the television.

If the issue is still unresolved after following all of the troubleshooting steps, service may be required. Please note the number of times the STANDBY light flashes and relay that information to the service center.