When TV is turned on we get no picture or Audio Hitachi 46ux25k

are you using an HDMI cable? is it a cheap thin cable or heavy duty?
HDMI cables carry sound but it's possible you don't have it seated completely or it's a cheap cable. or your audio settings on your TV are not set to HDMI if that's the cable you're using. try running your audio setup on the TV Menu.

The main power supply regulator section circuit fault. Either it will be a separate board, or the part of main board. Check and replace damaged component/s at its main power regulator [SMPS] section circuit. Contact any service technician. If you wish to get some details; check the site linked here. Pull up older posts.
http://electronicshelponline.blogspot.com/
It will be best to replace the power supply regulator board as card basis rather than making "Surgery" to it; which usually will make loss for both money and time. Even though you can make it right, it will cost around an amount equal to the cost of a new board; including the cost of (spare parts + service charge) More to say, most of the spare parts to it will be difficult to get from open electronic spare part market. This is true to most of the flat panel TV power supply boards; irrespective of its brand and screen size.

You need to replace both of the STK ICs STK392-110s
Mats has ICs 1-800-628-1118
they are big black ICs and will have PN on them. check all of the small ohm resistors RK46,50 52 58,60

Hitachi Ultravision power light on but on picture

it is problem your TV high voltage unite(EHT)
change it by authorised service centre

my sony television is not showing a picture of have no sound, you hear the tv click on but nothing moel number is KP-41T65

Ur high voltage flyback transformer is dead.
U need a new one.

look in back fo tv on curcit board left side there should be two regular 125v 1.5 amp fuses see if they are black or wire in side is broken

When you turn on the TV do you hear 3 clicking noises then the TV turns off?

Research at www.HitachiServiceUSA.com ........T.