Re: LG 50PQ6000 unstable 5v standby
That is fine, the PFC is switching off.
That is fine, the PFC is switching off.
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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. -
Re: LG 50PQ6000 unstable 5v standby
Wow something works!
Repaired: LG50PQ6000Comment
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Re: LG 50PQ6000 unstable 5v standby
so why does it go nuts when I plug in the Y-sus and Z-sus boards?Repaired: LG50PQ6000Comment
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Re: LG 50PQ6000 unstable 5v standby
Perhaps the low 3.5V is causing problems with the rest of the logic.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
Another area I have a question mark over:
ACDETECT with the board dissconnected from the TV jumps about with the clicking but never over 1v?
maybe a clue to you guys?
When I connect the board to the TV it gets the 3.5VDC somehow.Repaired: LG50PQ6000Comment
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Re: LG 50PQ6000 unstable 5v standby
Me too.
What does the manual say about the ACDETECT? I.E., does it say that when AC is detected, the ACDETECT pin is high? low? what about if there is a power failure (AC power drops out, due to power outage, or being unplugged)?Muh-soggy-kneeComment
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Re: LG 50PQ6000 unstable 5v standby
AC Detect is generated on the SMPS, by rectifying a small sample of the
A/C Line at D102 and associated circuitry and routed to the Controller (IC701) where it outputs at pin 15 and sent to P813
pin 18 to the Main Board where it is sensed and monitored by the Main Microprocessor (IC1). The AC Detin this set works differently than most. If AC Det is missing the Microprocessor will turn off the television in about 10 seconds after turn on.
This will happen each time turn on is attempted.Repaired: LG50PQ6000Comment
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Re: LG 50PQ6000 unstable 5v standby
PIN:18
LABEL:AC Det
STBY:5V
RUN:5V
DIODE MODE:OpenRepaired: LG50PQ6000Comment
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Re: LG 50PQ6000 unstable 5v standby
That would mean that when there is AC, the ACDETECT would be high, as it is when the mainboard is connected in your case.
I don't know why it would be low with no mainboard, but I think some of the filter caps next to the small heatsink on the bottom right could be dried up inside.Muh-soggy-kneeComment
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Re: LG 50PQ6000 unstable 5v standby
ok the 3 capasitors? I will remove and test tomorrow. It looks like there is another rectifier, an IC and another thing with 3 legs fitted to the heat sink.
So it this like another 5v supply circuit and those capasitors are filtering out noise?Repaired: LG50PQ6000Comment
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Re: LG 50PQ6000 unstable 5v standby
Manual said its the STBY 5V, 5V, 12V SourceRepaired: LG50PQ6000Comment
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Muh-soggy-kneeComment
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Re: LG 50PQ6000 unstable 5v standby
Do you need the back also?Repaired: LG50PQ6000Comment
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Re: LG 50PQ6000 unstable 5v standby
MANUAL:
AC Voltage is supplied to the SMPS Board at Connector SC101 from the AC Input assembly. Standby 5V is developed from
160V source supply (which during run measures 380V measured fromthe primary fuse F302).
This supply is also used to generate all other voltages on the SMPS.
The STBY5V (standby) is B+ for the Controller (IC701) on the SMPS and output at P813 pins 11 and 23 then sent to the
Main board for Microprocessor (IC1) operation.Repaired: LG50PQ6000Comment
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Re: LG 50PQ6000 unstable 5v standby
If possible. I suspect the 5V MAIN is derived off here...
If the 12V is also low by about the same amount (30%), then the suspect would be the primary side, controller IC, or TL431.
I say TL431 because I now recall budm had a Samsung monitor with low rails, and it turned out to be the TL431 (voltage reference IC; for the feedback loop.)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
Rear of low voltage board area.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 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,
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 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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