Our philips lcd tv picture turns off but sound stays on and then the piture won't come back on for longer while.

Quite possibly one of the heat sinks has come loose or a power supply cooling fan has failed.
Have you tried blowing it out using canned air?

If the backlight of the LCD-panel does not function, (no picture) then Master and/or Slave inverter are defective. Inverter boards are screwed to both sides of the LCD display, if they have revision 1.2 boards then they will need replaced with revision 1.3 boards.

Make sure the cooling to the TV is not blocked. It is on all the time even when off. Some of the spply cucuits remain on continuously. try uplugging the unit. Let it cool. If it is an older TV the back lighting may be dieing, then it is Tech. time

With a bright flashlight see if you can see a picture.. If you can this indicates your invertor board has failed. If not more than likely your main video board has failed. Ebay has tons of parts for these tv's.

Sounds like a bad main board

well this could be a power supply issue try this web site they could have the part www.discount-merchant.com
Ness

Your tv is being attacked by electrical surges which seem very violent and has already damaged some logic controls. Please invest in a AC filter which will protect your tv from such spikes....... but first you need to get your tv serviced from the electrical damaged it has already suffered.

I reset the comcast cablebox. I totally unplugged the cablebox for 20 seconds and then plugged it back in. Turned on both the cablebox and the tv and the HDTV channels operated correctly.

tbrace, your picture tube is getting a little tired, the "IK circuit" is causing the blanking of the video because the tube is not returning a large enough signal back to the IC that monitors it. Theres only one fix (besides replacing the tube) for your set and that is to turn up the screen control. You have to remove the back from the set and on the right hand side there is a large plastic part called a flyback transformer, with a heavy wire coming out of the top which goes up to the picture tube, mounted on the front of this transformer is 2 black blastic "philips type" controls, one over the other look closely and one will be marked focus(do not turn that one) and the other is the screen control, turn the set on and SLOWLY turn the control clockwise until you see a bright picture with white lines in it, once you see the lines turn it back until they disappear, (check several channels to be sure they are gone) your done, may last 3 weeks, may last a year, it`s all you can do, BMW Rider

phillips 17in lcd no picture