I have a vizio l32hdtv10a that doesn't turn on fully. i plug it in and without pushing the power button, the power light turns green. I also can't turn it off without unpluggin it. I have noticed that the remote 3.3v signal that turns the power supply on fully is not existant, it shows no voltage whatsoever. I have already pretty much determined that the main board is bad. What i'm really trying to figure out now is, 1. is my power supply working properly? and 2. is my lcd inverter board working properly? I tried supplying my own seperate 3.3v signal to the remote pin on the power supply. It seems to show healthy voltages on all pins. the 24v pins are showing proper voltage, the 5v pins are showing proper voltages, and the 12v pins show proper voltage. But my main question is, if i get power supply to turn on fully with everything hooked up properly, shouldn't the backlight atleast turn on? whether there is a faulty main board or not? or does the mainboard somehow control the backlight and let it turn on? I'm showing voltages going to the lcd inverter board but none of the lights are on, and only one half of the lcd inverter board seems to have power flowing. some help would be appreciated, i'm almost at my wits end with this thing. I don't want to have to order more parts than i need.
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Re: testing vizio L32hdtv10a
First, stop and take a breath once in a while. The single long paragraph is overwhelming.
Next, pictures help us help you. A single picture taken from directly above the main board would be appreciated.
Vizio had a problem with U33, a 1117 class (AS1117, LM1117, etc) LDO regulator on several of their TVs. Before you get too excited, see if there is a U33 on the main board. Your symptoms do not match exactly. Or I misread what you were trying to express in the flood of words.
The inverter is controlled from the main board. Signals to turn it on and set the brightness are sent late in the start-up sequence.
PlainBillFor a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.
Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic. -
Re: testing vizio L32hdtv10a
sry for the long paragraph, i was just trying to be descriptive and thorough about the problem i am having. I'm not sure where U33 is located on the main board. I have looked and looked but most of the letters and numbers are too small for me too read. I tried to attach a pic of main board but it won't upload for some reason. So your saying that the lcd inverter won't turn unless instructed by the main board or? So if i replace the main board, will the tv work properly again?Comment
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Re: testing vizio L32hdtv10a
You know this is the 2nd time PlainBill and others have told you to check U33.
From your previous thread ...
https://www.badcaps.net/forum/showthread.php?t=17312
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Re: testing vizio L32hdtv10a
i have looked and looked, i can't find U33. could someone point out to me where in this picture u33 is?Attached FilesComment
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Re: testing vizio L32hdtv10a
Not on that picture. I can barely count pins on the LDO regulator, let alone component IDs. You may have a different main board.
If you look at the picture, near the top center is a symbol consisting of an interlinked LF (probably indicating Lead Free). Just below that symbol is some text, to the right of the text is an LDO regulator, it probably has a part number of AS1117. Note that pin 1 is on the bottom, the middle pin and the tab are identical. U33 (if it exists) will be identical to that. There is another IC in an identical package about 1/3 of the way up from the VGA input (blue) connector.
With the main board and power supply screwed in place, the TV plugged into an AC outlet, and power on, measure the voltage on the three pics of each IC in an identical package. Report the results.
PlainBillLast edited by PlainBill; 12-14-2011, 07:40 AM.For a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.
Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic.Comment
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Re: testing vizio L32hdtv10a
yea, my camera is kinda crappy. sry for the blurry pic. I tested with voltmeter and found no voltages whatsoever on any of the pins for the components u mentioned. And I am pretty much certain that this board has no U33. I looked for hours.Comment
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For a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.
Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic.Comment
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Re: testing vizio L32hdtv10a
yes, there is one fuse on the board. I checked it with a test light, it is in working order.Comment
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For a number of reasons, both health and personal, I will no longer be active on this board. Any PMs asking for assistance will be ignored.
Never be afraid to try something new. Remember, amateurs built the ark. Professionals built the Titanic.Comment
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Hi and thanks in advance for any input you might provide!
I have a Sceptre U550CV-UMRD8POTV83BB 4K LED (this is a dumb tv) that I bought new in August 2021, so It's just completed 3 years.
Main power board model: TP.MS3683.PC821 T-Con board: N4TP546UHDPU2L_BO
Last Sunday I was watching a dvd and fell asleep for about half hour, when I awoke the tv screen was black and couldn't get the dvd menu to show, so I changed the input to antenna and had sound but no picture, turned it off. I then got online and found this great site! ....read many troubleshooting tips and this... -
Hey guys great forum glad to have found it. I bought a Sony XBR 65X900C cheaply because it didn't work. No signs of life at all not even a light/led. All I hear is a brief high voltage sound when I throw the power to it.
Didn't see any obvious signs of damage so right away started checking voltages. This is what I see:
Power Board Connector that goes to Main board
CN6401
Pin 01 NC
Pin 02 NC
Pin 03 "BL_ON": 0V
Pin 04 "N/C"
Pin 05 "STBY 3.3V": 3.5V
Pin 06 "GND": N/C
Pin 07 "AC_OFF"... -
ONN 100012588
Issue: No Power, Then Rebooting After Main Board Change
Short answer: replace main board and power board
Technical answer: replace main board and Q306 & Q307 on power board.
Long answer:
TV wouldn't turn on. Power switch was fine which means the main board isn't processing the power on signal. Replaced main board. TV turns on now but randomly reboots. Bad main board? EEPROM? Tried to pull main board and got a shock touching the corner of the board. That's weird. C334 (450V 10uf) capacitor is still holding a high charge.... -
Hi, this is my personal laptop, which the original board (lets call it Board A) blew up PU8700 (TPS51486), making a hole on the board, i had left the laptop at my desk one day with the battery fully charged and didn't touch it for a week, but when i tried to turn it on it didn't
Thought the battery was dead, so i plugged in the charger then tried to power on, the power LED blinked once, charged LED still orange, unplugged the charger, plugged in again and I noticed the "magic smoke" smell, so i unplugged the charger, removed the back cover and saw the blown IC (the "magic... -
I suppose the real question is whether the existing pinouts from ether a 17IPS71 psu are cross compatible with a 17IPS12 psu? If they are then the exchange of the main boards should have no issues providing the screen is compatible with both main boards. Obviously you can change the screen configurations easily enough (providing you have the correct files) for the main board. Why may you ask would I do this? Well a lot of the smart features are no longer working on a Hitachi 48HBT62U main board I wish to give it a new lease of life!
Obviously the same LVDS connector for the screen connection...
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