Hitachi TV no longer turns on after power failure

N

navagator

Audiophyte
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1
#1
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
 
XEagleDriver

XEagleDriver

Senior Audioholic
Ratings
232 1
#2
Two ideas:
1) Did you verify the wall outlet has power, plug in a lamp/check the fuze box?
2) If not the above, it may be more mechanical than electrical. A loose connection or wire in the tv.
3) IMHO if the power on/off had caused a voltage or current surge and damaged the tv circuits it would not have worked in the garage.
Good luck with this mystery or newly haunted house!
XEagleDriver

Sent from my LG-LS993 using Tapatalk
 
BoredSysAdmin

BoredSysAdmin

Audioholic Overlord
Ratings
5,289 19 32
#3
I had pretty much same "mystery" happen to my house very recently. Have an ac outlet in the basement which had no power after very similar AC power on/off/on event.

Turns out it was a GFI outlet and it's GFI breaker was in the garage. It was indeed tripped. resetting it brought the power back.
 
N

navagator

Audiophyte
Ratings
1
#4
Two ideas:
1) Did you verify the wall outlet has power, plug in a lamp/check the fuze box?
2) If not the above, it may be more mechanical than electrical. A loose connection or wire in the tv.
3) IMHO if the power on/off had caused a voltage or current surge and damaged the tv circuits it would not have worked in the garage.
Good luck with this mystery or newly haunted house!
XEagleDriver

Sent from my LG-LS993 using Tapatalk
Thank you for your reply.

The wall outlet is fine, I actually had it plugged into a surge protector and it is working fine. I also tried it in a couple of other outlets in the house on different circuits and it didn't make any difference.
I agree with you, I don't think it was a power surge either because as you said it worked great in the garage. I also had other things plugged into the surge protector and they're fine.
 
andyblackcat

andyblackcat

Senior Audioholic
Ratings
175 6
#7
Possibly and likely the PSU has failed that is the power supply board. Look inside again there should be a part number on the power supply. Look about on the internet try ebay there may be some spares? But I had same thing with one my DVD players and laserdisc player the PSU has failed its not a big deal to get replaced with a working one unless you like checking all the components on the printed circuit board with a multi-meter and then its just question of getting that part doing some un-soldering and soldering the new part/s in place and it should work.
 
N

navagator

Audiophyte
Ratings
1
#8
Possibly and likely the PSU has failed that is the power supply board. Look inside again there should be a part number on the power supply. Look about on the internet try ebay there may be some spares? But I had same thing with one my DVD players and laserdisc player the PSU has failed its not a big deal to get replaced with a working one unless you like checking all the components on the printed circuit board with a multi-meter and then its just question of getting that part doing some un-soldering and soldering the new part/s in place and it should work.
Your probably right.

I might consider trying to replace the PSU if I could find one, however I can't make out the part # on the board. "DP5X -Power P.W.B" is printed in white but the other number directly underneath printed in black reads " DP5??07 3389. I can't make out 2 of the numbers.

Otherwise it's probable time for a new tv.
 
andyblackcat

andyblackcat

Senior Audioholic
Ratings
175 6
#9
If you like to consider that option for repair or newer one.
I looked on ebay least I only had to on google with "hitachi 57f710e power supply ebay" I didn't see anything showing up. I not sure maybe other power supplies made for a later model maybe the same or it might be flat screen option now sorry to say.

Also if haven't got a multi meter get fair decent one cheap on ebay or amazon and look for the fuse on the PSU it would like be located near to mains voltage input terminals if that is blown then get a new one of same value and hope it powers up? If it doesn't then its something else on the PSU that has failed. I read around and one other owner believes its a capacitor.
 
Last edited:
N

navagator

Audiophyte
Ratings
1
#10
I decided that I would try to remove the PSU and take a better look at it. But unfortunately there's a plastic frame around it which is attached with 3 screws. The 2 in back were no problem to remove but the one in front is to far up for me to remove. I assume the whole chassis would probably slide out, however I know I would have to remove the 3 main CRT wires from the deflector board in order to do so, and I know that's dangerous, so I won't.

But I was able to push the PSU over just enough so I could see the back of the board and I noticed that the solder joints of one of the capacitors ( If you look at the picture it's the larger one toward the center of the board ) had a brownish rust like material around the solder where it meets the board. It was the only solder joint that I could see that was that way. Could that cap be bad? It's not bulged or domed that I can tell.
TV Cap 2.jpg
 
andyblackcat

andyblackcat

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Ratings
175 6
#11
Seems likely capacitor has been oozing due to some overload in heat.
I can see three black relays on the board.

Find that fuse and get a multi-meter to check it unless its glass type where you can hold up against light to see if the coil is broken?

And yes do not touch it there maybe still some voltage left in those capacitors and they'd give you a nasty JOLT so be careful!

Sometimes it is possible for the relays to fail as I had to replace one or two on amplifier for a newer type that has better voltage handing due to the older type that was a common fail.
 
N

navagator

Audiophyte
Ratings
1
#12
Seems likely capacitor has been oozing due to some overload in heat.
I can see three black relays on the board.

Find that fuse and get a multi-meter to check it unless its glass type where you can hold up against light to see if the coil is broken?

And yes do not touch it there maybe still some voltage left in those capacitors and they'd give you a nasty JOLT so be careful!

Sometimes it is possible for the relays to fail as I had to replace one or two on amplifier for a newer type that has better voltage handing due to the older type that was a common fail.
I was also curious about the relays. As I said when I had it in the garage I could hear a fairly loud click when I plugged it in. When I first brought it back in the house I couldn't hear the click at all. But I can now, however it's still not as loud as it was outside and the little LED's on the deflector board don't light up.

The fuses are the glass type and all are ok.
 
andyblackcat

andyblackcat

Senior Audioholic
Ratings
175 6
#13
So fuse okay. Its got be one of the other components but need a multi-meter volt meter to check if there is open circuits where the component isn't working or won't register on the multi-meter.

If you checked the input with multi-meter you may see 120v passing in but may not be making its way around the rest of PSU due to failed part.
 
N

navagator

Audiophyte
Ratings
1
#15
I've pretty much give up on it at this point, I'm looking for another tv.

I was able to remove the PSU after all. But I couldn't see anything visibly wrong other than the large cap that I thought might be bad. I removed it from the board and it looked fine underneath.

Thanks for everyones help.
 
afterlife2

afterlife2

Audioholic Spartan
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2,374 12 3
#16
I've pretty much give up on it at this point, I'm looking for another tv.

I was able to remove the PSU after all. But I couldn't see anything visibly wrong other than the large cap that I thought might be bad. I removed it from the board and it looked fine underneath.

Thanks for everyones help.
Did you email shopjimmy?
 

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