Hitachi 57F710E rear projection no longer turns on after power failure

Discussion in 'Troubleshooting and Repair' started by navagator, Aug 10, 2018.

  1. navagator

    navagator

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    I have a Hitachi 57F710E rear projection tv that won't turn on. We recently had a power failure, the electric went off and on, off and on, and then off and stayed off. This happened in quick succession. After the power was restored the tv wouldn't turn on. I took the back off of the tv and checked to see if there were any fuses that might have blown. There was 4 fuses, 3 on the power supply board and one on another larger board that I believe says "deflector" on it. All the fuses were fine. We did the unplug and plug in thing like the book suggested and it didn't work, we even left it unplugged for 72 hours and plugged it back in, it didn't work. So, we decided to just move it out to the garage to get it out of the way. After we moved it out there I decided I would take the back off and take one more look at it. after I took the back off I plugged it in and I heard a slight click, it only clicked once. I also noticed that there was a small green LED light on the deflector board that was lit up, so I pushed the power button on the front of the tv and I heard the tv come on. I went ahead and hooked a dvd player up and lo and behold the tv was working fine. At that point I decided to go ahead and clean all of the optics. I then brought it back into the house and hooked all the STB's back up and plugged it in. The tv wouldn't turn on. It no longer makes that small click noise when I plug it in and the little LED light on the deflector board no longer lights up.

    Could someone give me an idea of what could be wrong.

    Thanks
     
    navagator, Aug 10, 2018
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  2. navagator

    kellys_eye

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    Sounds typical of swollen capacitors in a PSU section - such intermittency is indicative of it.
     
    kellys_eye, Aug 10, 2018
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  3. navagator

    WHONOES

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    Has the socket you normally plug the TV into failed?
     
    WHONOES, Aug 10, 2018
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  4. navagator

    navagator

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    Thank you for your reply.

    I looked to see if there were any swollen caps but didn't see any but I might have overlooked one, I'll take another look.
     
    navagator, Aug 10, 2018
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  5. navagator

    navagator

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    Thank you for your reply.

    No, the socket is fine. I actually had it plugged into a surge protector and it's working fine. I did however try it in a couple of other outlets in the house on different circuits and it didn't make any difference.
     
    navagator, Aug 10, 2018
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  6. navagator

    WHONOES

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    Thinking about it a bit more, it sounds like it is something to do with moving the unit. It could be something like a crack in a pcb in the switch area that opens and closes when you move the TV or something like that.
     
    WHONOES, Aug 10, 2018
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  7. navagator

    kellys_eye

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    Could also be a simple dry solder joint. You could try poking the PSU boards (with a suitably insulated stick) whilst trying to power on.

    Flex the boards a bit and see what happens.

    (Whonoes beat me to it!)
     
    kellys_eye, Aug 10, 2018
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  8. navagator

    WHONOES

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    Yeah, could easily be a dry joint.
     
    WHONOES, Aug 10, 2018
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  9. navagator

    Cannonball

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    You might try freeze spray on the suspected area. Intermittent problems are hard to pinpoint. Try freeze spray when it doesn't work and use a hair dryer to heat it when it is working. Good Luck.
     
    Last edited: Aug 10, 2018
    Cannonball, Aug 10, 2018
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