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Rod
Rod, TV & Communications Sys Repair
Category: TV
Satisfied Customers: 4501
Experience:  FCC Commercial License, Previous owner of Electronics Repair shop, 40+ years in electronic systems.
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Hello, My hitachi 55hdt79 tv screen went blank, still hear

Hello, My hitachi 55hdt79... Show More
Hello, My hitachi 55hdt79 tv screen went blank, still hear the sound, and still responds, just can't see anything. Took the back off the tv, and the seems the power supply around 2 capacitors seems to be humming slightly, might be common. P.S. LSJB1224-1<br/>Thanks!
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Hi,

If you press the menu button, does the menu come up?

Thanks,
Rod
Customer reply replied 6 years ago.
Nope, nothing comes up to the picture, you can hear the sound, turn off and on, but no menu, or anything. Screen stays black.
Hi,

Do you hear any clicking (repeated - one is normal)?

Thanks,
Rod
Customer reply replied 6 years ago.
took a second look around it, one relay clicks once when you first turn it on, only other sound i can hear is the 2 caps upper left have a slight buzz. Very faint though. I am industrial Maintenance, So i have better understandings some what. Anything you want me to check, just ask.


graphic
Hi,

The buzzing is the switching transformer - that is normal.

Hitachi does have a service note with the problem - it is the panel logic board - not passing the VCe Go signal for the Y-driver voltages (which are the voltages that provide the power to the plasma display). Normally when there is a failure of the Y-driver cards, the TV will shutdown. There is a remote possibility the Y-sustain (which feeds the Y-driver boards and their signals) might have a fault - rather than the logic board - but the first tests are with the logic circuits on the logic board to see if the "Go" signal is passed to the power supply to enable the voltages.

Do you have some test equipment to verify, such as a logic probe and a VOM - as the boards run about $400 new, and without verifying which board or circuit it is - not good to just replace a board and find it is another circuit?

If not, a service estimate will run about $45-$75, depending on your location. The estimate charge will apply towards labor for repairs, should you decide to have it repaired.

Thanks,
Rod
Customer reply replied 6 years ago.
All I have is an amp meter at home, have vom and a probe at work i can borrow, but will be tomorrow before i get them. I was looking at the powers supply my self, kind looks like part of the tv was getting power, but not all of it. I was watching it when it went out, no pop, or snap, like i turned the tv off, but the sounds was still there. Your logic sounds better then mine, so think i will go with the logic board and give it a shot. The logic board ND25110-D013. Do you repair or do you know were i can get one at. Bebuilds are ok with me too
Hi,

The board part number should be FPF31R-LGC0053.

However, I am going to have to opt out, as the firmware may not be current with the board and I cannot provide you with the firmware - it is restricted to servicers to upgrade.

Thanks,
Rod
Customer reply replied 6 years ago.
I will find one. Thanks for all your help and your time.