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Toshiba 40G300U failure

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Offline pimpin

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Toshiba 40G300U failure
« on: 02 March 2013, 07:01:24 PM »

i have a LCD F/S that is about 1 1/2 to 2 years old tops.  It started making a faint buzzing noise which became a bit loader as the week went on.  it would come and go a bit but was there most (almost all) of the time.  it sounded almost like two piece of metal brushing each other (if it had moving parts i would be looking for signs of wear as it were.).  The picture had a SLIGHT flicker to it every now and then but nothing huge.  my kids were watching it the other day and the picture just died on them.  The sound is fine by the way, it turns on/off no problem and it functions fine.... just no picture.  If i press the input button on the remote and choose Sat or HDMI input or what ever it switches no problem and again i can hear sound but no pic.  LED (green) on light lights up and i believe there's a BRIEF flash of white light across the bottom of the screen when it powers on.  I found some testing instructions on a site the suggested removing the 802 plug and testing pin 11 and 12 for 5v power.  I did so and the 5v was there constantly and steady when turned on (the test said it should only be there at power up for a brief period).  Pin 13 was supposed to be 0 i believe (which it was) and pin 14 was supposed to 3.6v but it was showing 0.  SO... according to the diagnostic it indicates that i have a main board issue.  I have looked for obvious signs of damage but nothing such as a big bulge in a capacitor or anything obvious like that.  About 6 months ago there was a VICIOUS once in a lifetime lightning storm (
if you're interested) that passed through our area and one of the strikes in the video hit about 200 m or so from our house (REALLY scary).  It trashed my WD HDTV box and my router that was hooked up to the network and it MAY have caused some damage to my digital hook up between the receiver and the box as well.  I don't believe it did any damage to the TV as it was working fine afterwards right up until this week.  Anyway... i would like to know if the tests and results indicated are pointing towards a mainboard issue and if so how do i identify the culprit or am i just going to have to replace the entire mainboard?  Thank-you for your help.