Re: LG 60lb5200 LCD TV - No Power - No Standby Light
Pin 1 or the Vcc reads 1.02 volts.
Landon6544
Member
Last Activity: 06-01-2021, 11:04 PM
Joined: 12-15-2017
Location: Greenville, SC
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Re: LG 60lb5200 LCD TV - No Power - No Standby Light
What do I need to test to isolate the IC chip as the culprit?Leave a comment:
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Re: LG 60lb5200 LCD TV - No Power - No Standby Light
Ok, this is actually the same model that another member is having issues with, and you asked him the same question. He's getting voltages on his pins, however. They're just too low.
Anyway, the printing is clearer on his IC chip. I've included the manual for it....Leave a comment:
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Re: LG 60lb5200 LCD TV - No Power - No Standby Light
Man... I'm really having trouble reading it. Might need to find a magnifying glass. If I can determine that it IS the IC causing the issue, I might be able to get it fixed. I don't have the tools for soldering something that small.Last edited by Landon6544; 12-18-2017, 12:38 PM.Leave a comment:
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Re: LG 60lb5200 LCD TV - No Power - No Standby Light
Ha, it looks nothing like those colors on my board, but it's reading 10.6k. So, even though it looks burnt, it seems to be reading within tolerance? And... I don't see any IC chips on the power board. Do you mean on another board?Leave a comment:
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Re: LG 60lb5200 LCD TV - No Power - No Standby Light
Oh wow... I just noticed that the board is burnt underneath that resistor. The ohm reading is 11, 700 Ohms. I can't tell what colors the stripes are, though....Leave a comment:
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Re: LG 60lb5200 LCD TV - No Power - No Standby Light
Well, I initially assumed that D stood for "diode", but the component has three terminals, although there's also an 'M' designation there. I can't read the part number because of the heat sink. I only learned basic electronics, and that was in Air Force tech school back in 2002. So... I'm learning and refreshing. The heat sink on the hot section is attached to similar looking components, but they have a Q. I'm guessing those are transistors.Leave a comment:
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Re: LG 60lb5200 LCD TV - No Power - No Standby Light
A bit more... D3 and D9. Are those MOSFET transistors? I'm learning a lot already. Haha. I'm pretty sure the noise is coming from the varistor, or brown box down near the fuse. Is that supposed to have loose pieces inside?
I also tested the bridge rectifier on the hot side. Getting 167v DC across the positive and negative terminals, and around 120v AC on both of the middle inputs.Leave a comment:
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Re: LG 60lb5200 LCD TV - No Power - No Standby Light
C9 and C10 both read 167v DC.Leave a comment:
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Re: LG 60lb5200 LCD TV - No Power - No Standby Light
Ok, I checked D3 and D9. Those are the three terminal voltage regulators on the DC side, right? I'm getting 0 volts.
Also, I noticed when I move the board that I hear something rattling in one of the components. Sounds like little pieces of loose glass or metal. Could that be from the transformer?Leave a comment:
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LG 60lb5200 LCD TV - No Power - No Standby Light
Hi. Just bought a repair project. LG 60lb5200 has no standby light. I've tested the pin voltages on the power supply and get nothing on any of them. The symbol on the bottom pin reads 'EN'. I assume this is the standby voltage out? I've searched other posts, but can't find this abbreviation mentioned. I tested the main transformer outputs and got nothing. The fuse is good and reads normal AC voltage across it. Can someone lead me in the right direction with narrowing down the problem component? I'd rather not have to pay $100 for a new board.
I've included pics.
Thank y... -
Re: New Members - please post your introductions here
Hi! My name is Landon. I love computers, scripting, and anything to do with electronics. I was an Avionic Sensors technician with the Tulsa Air National Guard. I'd like to start fixing Tvs as a hobby. I was given a Samsung LCD, and replaced the caps for my first repair job. I just bought a 60 inch LG and am currently researching power supply issues.
Thank you!Leave a comment:
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