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Repaired: LG50PQ6000 -
Re: LG 50PQ6000 unstable 5v standby
OK, looking at the layout, it seems that the 12V is switched on through a MOSFET. It is always present, but only presented to the main board as required.
There is a jumper link, it looks like J22. Can you get to this from the top side?Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: LG 50PQ6000 unstable 5v standby
Yes I can get a probe on J22
Repaired: LG50PQ6000Comment
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Re: LG 50PQ6000 unstable 5v standby
OK, it should measure:
12V +/- 0.5V, if there is a fault on 5V side.
Not 12V (possibly around 9V) if there is a fault on the primary or TL431 fault.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: LG 50PQ6000 unstable 5v standby
0vDC to GND spikes to -0.1mV when the relay clicksRepaired: LG50PQ6000Comment
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Re: LG 50PQ6000 unstable 5v standby
Hmm OK I will need to rethink this!Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: LG 50PQ6000 unstable 5v standby
Can you see the components ok? Would you like me to shout out any numbers?Repaired: LG50PQ6000Comment
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Re: LG 50PQ6000 unstable 5v standby
Can you get a little wider shot of the back (green side) -- include the transformer pins.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: LG 50PQ6000 unstable 5v standby
Just a side note, not going to try and distract you from tom66's expertise! xD
IC201, is a 5v regulator. I bet that it regulates the 5v standby. It looks to be a KIA278R000PI. It's max input voltage is 10v. Could it be failed from 12v input?
You thinking that the rectifying diode is shorted out?Muh-soggy-kneeComment
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Re: LG 50PQ6000 unstable 5v standby
Any better?
Attached FilesRepaired: LG50PQ6000Comment
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Re: LG 50PQ6000 unstable 5v standby
Sorry just read the post again you ment D351Repaired: LG50PQ6000Comment
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Re: LG 50PQ6000 unstable 5v standby
Can you test these like normal diodes?Repaired: LG50PQ6000Comment
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Re: LG 50PQ6000 unstable 5v standby
Hm yes, D351.
I say that you should replace it. How did you measure it? did you have your negative probe on the center pin, and your positive probe on the outer pins (one at a time)? These are dual diode packages, and I am guessing the common pin is the cathode, based on the PCB layout (filter capacitor after the dual diode).
If one of them reads short, try reversing the meter leads. If it still reads short, take the diode off the board, and measure. If it still is shorted - it's bad, causing the voltages to be wonky, and overloading the SMPS IC.Muh-soggy-kneeComment
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Re: LG 50PQ6000 unstable 5v standby
0.22v one way and 0v the other on both diodes in the component. (Diode removed from board and tested)Repaired: LG50PQ6000Comment
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Re: LG 50PQ6000 unstable 5v standby
Thanks for the big photo but I meant just a little bit expanded around the same area, not the whole board. I am trying to figure out where the 12V comes from.Please do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Re: LG 50PQ6000 unstable 5v standby
This is all I have from another TV. The PSU is very simular but the rest of the TV is different from what I have found out so far.
I did have to remove C351 to get the D351 out and do have a funny reading but my capasitence meter isnt amazing I have to admit. ITs just a setting on my DVM.Repaired: LG50PQ6000Comment
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Re: LG 50PQ6000 unstable 5v standby
Its hard to avoid flash reflection but hope this helps.Attached FilesRepaired: LG50PQ6000Comment
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Hi. I got a Vizio with no power or standby, and won't turn on with remote or button. I checked the voltages on the connector and all read 0.00V or nearly 0(0.050 ON/OFF pin). None of the pins are labeled STB for standby although I do see some 5V pins. Other than the obvious standby led, which isn't coming on, is there a way to check for standby voltage on this PS. I'm trying to see if my problem is the PS or mainboard. Some Vizios I have fixed with no standby led me to think it was the PS but it turned out being the mainboard. Any experience with this set would be greatly appreciated. -
Hi all.
I started a thread while back regarding TV power supply standby circuitry as it is something I am not quite on top of.
SMPS theory and function is becoming more familiar, however the standby part is still a bit of a mystery.
Anyway, a friend has this TV with the above mentioned power supply board which has no standby voltage, nor any other voltages leaving the board.
The mains AC comes in fine, gets filtered and rectified with power is on the main filter cap as well as the transformer and drain pins of the ICE3B0665J, but that's it.
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Hello,
I am trying to re-purpose this power supply that I saved years ago from a tv with a cracked screen for a monitor but that is not really that relevent at the moment. I do not recall which tv but a google search looks like it is from Wharfedale LTF37K1.
You may notice I made some alterations moving some components to the top and some wires which are from a 5v regulator I fitted to the 12v output as the monitor requires 5v. The standby was already at fault from the beginning, it has nothing to do with the alterations...
Years ago it had some bulging caps... -
Hello forum. I've recently been given a Yamaha TSX 120 DAB radio and ipod dock. Its working well however when put on standby its using 6.3 watts. The manual states less than 1 watt on standby. I measured this with a plug in monitor which seems accurate with other items. In use it uses around 7.5 watts. Firstly has anyone who owns a similar radio also got a plug in monitor to check if this is normal with this unit? In the first half a second the monitor shows 0.3 watts which I suspect is what it should use but something is switching it to be almost fully powered. I've searched the manual for eco...03-01-2024, 07:25 AM -
Hello everyone,
I got a Samsung The Frame 55 inch TV for free from uncle cause it is not turning on anymore. I am in the second year of training as an electrician so I have knowledge already but I am far away from to be a pro.
The TV has Standby but ist not turning on. A Friend of mine owns a 50 inch Frame TV so I checked the One Connect Box and the One Connect Cable there. Both are good and working normally. I have opened the TV case and measured some voltages on the Board.
What I already found is that the 12.8V are not an the connector to the main board connector to the power...
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