Tv shut off by it self?

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buckie
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Tv shut off by it self?


MODEL is a 47WXC43G 2year old I was watching TV and it just shut off i pushed the power button to turn it back on it would not turn back on I unplugged the TV then plugged it back in pushed the power button the light turn red for 5 sec and then off and blinked on and off 5 times I opened up the back the fuse was blown.I changed the fuse plugged the TV back in pushed the power button the light turn red for 5 sec and then off and blinked on and off 5 times .

Larry Dillon
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Bbuckie, cute pup!  Is this a

Bbuckie, cute pup!  Is this a Panasnic projection set, as you did not mention the make?  If it is, for future refferance, it is a Panasonic  PT47WXC43G.  Almost did not reconize the model.  First off, Did the set blow the fuse again?  Yes,  Most likly the Horizontal output transistor has shorted out because of cold solder connections on the flyback transformer, and or a bad capacitor in the sweep power supply and or, a bad flyback transformer.  If the set Did not blow the fuse again, then mopst likly you will have a problem in the main power supply where several parts in a kit form has and should be replaced all together.   What is the chassis number of this set, then I can see if I have any notes as to what kit it is going to need?  One word of warning.  In case you have had NO tV repair experience PLEASE do not attempt to make any repairs on this set , as it is very dangerous as there is alot of high voltage inside this puppy(Ha Ha play on words!)  Even when it is turned off! Good Luck and please keep us informed of the progress of this repair. 

TestUser1
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mine did same thing shutt off

mine did same thing shutt off by its self with no warning SANYO ds 25320 wall mart store last year.  about 1 year old now. i second the nice pup comment ,does he/she know any tricks? my beagle does ,he can balence a hot dog on his nose till i say <catch> he will then catch it ,and the whole thing gone in 2 bites.. what a dissapearing act, he has with them hot dogs.but he likes to watch tv greene acres is his favorite ,mine too timo 

buckie
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Panasonic  PT47WXC43G the

Panasonic  PT47WXC43G the fuse did not blow again. the chassis number is AP825 thanks

buckie
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Larry Dillon said: Bbuckie,

Larry Dillon said: Bbuckie, cute pup!  Is this a Panasnic projection set, as you did not mention the make?  If it is, for future refferance, it is a Panasonic  PT47WXC43G.  Almost did not reconize the model.  First off, Did the set blow the fuse again?  Yes,  Most likly the Horizontal output transistor has shorted out because of cold solder connections on the flyback transformer, and or a bad capacitor in the sweep power supply and or, a bad flyback transformer.  If the set Did not blow the fuse again, then mopst likly you will have a problem in the main power supply where several parts in a kit form has and should be replaced all together.   What is the chassis number of this set, then I can see if I have any notes as to what kit it is going to need?  One word of warning.  In case you have had NO tV repair experience PLEASE do not attempt to make any repairs on this set , as it is very dangerous as there is alot of high voltage inside this puppy(Ha Ha play on words!)  Even when it is turned off! Good Luck and please keep us informed of the progress of this repair. 

Panasonic  PT47WXC43G the fuse did not blow again. the chassis number is AP825 thanks

 

Larry Dillon
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I like Arnold the Pig too! 

I like Arnold the Pig too!  Were showing our age now with this talk!

 

buckie
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Did you find out any thing

Did you find out any thing buggs bunnie...

Larry Dillon
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No not yet, I put a call into

No not yet, I put a call into someone I know about a kit.  Will get back to you asap.

buckie
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Larry Dillon said: No not yet

Larry Dillon said: No not yet, I put a call into someone I know about a kit.  Will get back to you asap.

        thank you very much.

 

buckie
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 COULD IT BE A TRANSFORMER

 COULD IT BE A TRANSFORMER.T802

Larry Dillon
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Sure it could be the flyback

Sure it could be the flyback transformer. I thought I mentioned that from the word get go.

buckie
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No DC voltage at all Q801 has

No DC voltage at all Q801 has no voltages Transformer T801 HAS 9 VOLTS

Larry Dillon
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There is no power supply kit

There is no power supply kit for this model.  Do you have a service manual, or schematic on this set?  I looked and I do not have one.  Do you know how to read a schematic?

buckie
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Yes I have a service manual

Yes I have a service manual and schematic .No DC voltage at all. Q801 has no voltages Transformer T802 HAS 120 going in 9 VOLTS out. Transformer T801 has no voltage in or out flyback transformer no voltage.

Larry Dillon
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Ok if you want some good

Ok if you want some good sound advice,Is the manual in electronic form? As a PDF? Do you know how to compress, as I would really like to see the circuit. As I stated i have worked on these before, but this old brain is becomming frazzeled, as Im at 51 going to college, and man is it difficult to remember what I had for dinner last night after an english comp quiz or a physics exam! If you can send it, I will give you my E-mail and we can go from there. Or you can scan the circuit your talkin about and let me see it.

Larry Dillon
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ok Bucky, I looked over the

ok Bucky, I looked over the schematic, nice job of sending. Was able to reassemble no problem.. Ok you will bave the 9 volts on the T802 if the light is flashing and when you try to turn on the TV set, the relay clicks. This is the standby power supply and thats good. IC 801 and Q801, I would suspect first. This is a switch mode power supply circuit. The IC 801 is the regulator driver IC. Q801 is a mosfet switch mode regulator device. There are alot of small value resistors around the Mosfet device. I would, for sure check them too. T801 is the switch mode transformer. I have seen these bad in the past, but very rare. I would with the set off, Monitor the DC voltage on pin 8 of the IC801 and switch on the set. If the voltage spikes and goes down, I would replace IC801 and Q801 first. But of course do a static check of the gorizontal output transistor, look for cold solder connections around the sweep circuit and around the flyback transformer. Of course without the TV set here I can only make an educated quess, but this looks very simular to several pana. circuits I have worked on in the past.Oh on other thing, Make sure before you do anything, is to also check D817 and R814 as these are feedback loop circuit. Also double check ALL of the resistors, capacitors and diodes on the secondary of T801. Ok now if you do replace q801 and IC801, before you turn on the TV set, take out the main fuse, and jump across the fuse connections with a 100 watt bulb. This will incase there are any shorts hopefully stop these new parts from blowing up. If with the bulb, the set comes on, the picture will be a bit out of wack due to the bulb. You can then cross your fingers and put back the fuse and hopefully the set will work. Double ]check the b+ and adjust. If the light bulb lights up bright and stays bright, that will indicate that there is still a problem in the set somewhere. Now the bulb should glow bright and get dim if all seems good. Happy Searching!

buckie
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No voltage on Q801 0r T801

No voltage on Q801 0r T801 D17 R814  IC801  D801 has no voltage. Q801 looks brown gummy around it  on the board bottom and top.

wood
wood's picture
i have a 36 inch RCA hdtv

i have a 36 inch RCA hdtv model number MM36110 I believe. I don't know much about this tv since it was given to me as a gift. It has been working just fine until lately when it is beginning click off momentarily and then turn back on as if it is overheating as sometimes my stereo reciever will. is there an internal fan not working or does anyone have an answer for me? i would really appreciate some help

Larry Dillon
Larry Dillon's picture
buckie measure everything for

buckie measure everything for shorts.  On T801 pins 7 8 and 9 should be about 187 VDC.  If not check D 801 pin 1 for DC voltage.  There is a hot ground, and a cold ground on this set.  Make sure when you measure any voltages in this power supply on the primary side of T801 you use the HOT ground.

buckie
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I  removed  the fuse and  put

I  removed  the fuse and  put 100w bulb across it ,the  blub lites up when I push power but the bulb went out as soon as lit off, push the power bottom the lite comes on if you hold the button in it will still go out so every time you push the button the light come on then off?

Larry Dillon
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The reason it went out as it

The reason it went out as it does not see a short follow the instructions I left before. As to T801.

buckie
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Hello,  if Q801 is bad should

Hello,  if Q801 is bad should I also change IC 801.

buckie
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Hello RL801 is showing open

Hello RL801 is showing open when I  take a ohms reading from  the side that goes to T801 and R800, RL802 shows closed at the side that goes to R800 and RL801 is  both relays normally OPEN relays. does R800 make RL802 READ  CLOSED CIRCUIT WHEN MEASURING A CROSSED  IT . also there is no voltage on T551 flyback TRANSFORMER . thanks

Larry Dillon
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Ok let me look at the circuit

Ok let me look at the circuit .  I have it saved, i will get back to you on this tomorrow.

buckie
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Hello I changed Q801 IC801

Hello I changed Q801 IC801 and then I hit the power butten the tv played good for 5 mins boom fuse blowed ,Q801 went out again, now I hook up the 100Watt light bulb and I pluged in the tv to see what was going  on when I plug the tv in the relay clicked and the light bulb comes on for a sec and back out you don't have to even  hit the power butten just plug it in boom the light comes and goes out .if you leave the tv pluged in light blub  goes on and off and the relay clicks everytime the light comes on and off .

Larry Dillon
Larry Dillon's picture
See if Q801 shorted again,

See if Q801 shorted again, and did you use thye original numbers for the replscement parts, or did you use replacement numbers?  Check video out, Q705, 732, 761 and other components on the Cboard, also check Q218, 219, 220 on the A board.

buckie
buckie's picture
Hello yes I got the parts

Hello yes I got the parts from panasonic same part . I changed Q801 IC801 and then I hit the power butten the tv played good for 5 mins boom fuse blowed ,Q801 blowed  again, now I hook up the 100Watt light bulb and I pluged in the tv to see what was going on when I plug the tv in the relay clicked and the light bulb comes on for a sec and back out you don't have to even hit the power butten just plug it in boom the light blub comes on  and goes out .if you leave the tv pluged in the light blub goes on and off and the relay clicks everytime the light comes on and off .

buckie
buckie's picture
what I can't  understand why

what I can't  understand why Q801 went out, could D801 cause Q801 to blow or R800  . I am just  puzzled. the tv worked for 5 mins

Larry Dillon
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When the set was playing, you

When the set was playing, you need to make sure the regulator is working. measure the voltage on the secondary of T801 at the voltage points.

buckie
buckie's picture
I did there was 2 volt  on

I did there was 2 volt  on secondary t801

Larry Dillon
Larry Dillon's picture
Where did you measure two

Where did you measure two volts on the secondary at?

 

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