Re: LG TV 47LW5500 does not power on (PSU EAX62865401/Main board EAX64405501)
full board pictures attached
full board pictures attached
Attached Files
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Re: LG TV 47LW5500 does not power on (PSU EAX62865401/Main board EAX64405501)
Bump
anyone got idea what's wrong with it why its not getting full voltage or activating 12/24V supplyComment
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Re: LG TV 47LW5500 does not power on (PSU EAX62865401/Main board EAX64405501)
i response to you as first one and wrote that you listed wrong voltage.. its hard to to any one following if the OP do some things wrong.
so let from start just do this 2 things no more.
all test the power boards should be out from the TV testing as stand alone
- don't use any external resistor, solder jumper between stand by 3.5V and power on
now read the voltage on the main cab and the voltage on the out put socketComment
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Re: LG TV 47LW5500 does not power on (PSU EAX62865401/Main board EAX64405501)
1) You gave 220VAC at the two AC legs of the bridge rectifier, but your meter only shows 287VDC on the main filter caps instead of around 310VDC.
2) The Voltage on the main filter cap should jump to around 380 ~ 400VDC when PS-ON is applied to turn on the PFC circuit and the 12/24VDC power supplies.
3) The 12V/24V power supplies will not run unless PFC Boosted Voltage is present, if the PFC Voltage is low, the 12V/24V will stay in shutdown.
I attach the picture of the HOST SIDE power supply to show you the path of the circuit, you need to check the bridge rectifier, the two PFC Diodes, the resistance path all the way to the main filter cap to see why your meter only shows 287VDC, we need to get over 300V for the PFC to run, the PFC circuit may be in shutdown due to low Main DC Voltage.
You also need to see if there is switched VCC for running the PFC IC, so get the P/N of the PFC IC and look up the spec sheet to locate the VCC pin of the PFC IC.
Notes: the troubleshooting is being done based on the meter is OK per OP.Attached FilesNever stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809Comment
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Re: LG TV 47LW5500 does not power on (PSU EAX62865401/Main board EAX64405501)
@Diah I didn't meant int hat way I know you responded first on my thread and I apologize if you felt like I was saying noone responded to me.
@Budm thanks for detailed info, i'll check all component and update here.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
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