Re: LG 42LW4500-LB Need help with repair of PSU
The incoming mains of 230v ac is rectified to produce DC and then that DC voltage is increased by the circuit to approximately 380 - 400V DC.
There is no point in changing anything until you find that it is faulty!!!
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LG 42LW4500-LB Need help with repair of PSU
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Re: LG 42LW4500-LB Need help with repair of PSU
Originally posted by dick_barton View PostIt's very likely the set has powered down because there is a fault, however that is what you are trying to find. Nothing is blowing up or burning.
You really need a meter that has a 600V DC range to test that the mains supply is being rectified and is reaching the higher voltage parts of the circuits. For example to find out if you have 400V on those capacitors.
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Re: LG 42LW4500-LB Need help with repair of PSU
It's very likely the set has powered down because there is a fault, however that is what you are trying to find. Nothing is blowing up or burning.
You really need a meter that has a 600V DC range to test that the mains supply is being rectified and is reaching the higher voltage parts of the circuits. For example to find out if you have 400V on those capacitors.
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Re: LG 42LW4500-LB Need help with repair of PSU
Originally posted by dick_barton View PostThe attached picture looks like your power supply and if from an LG-47LW5700 model.
Can you check you have the voltages shown in the table.
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Re: LG 42LW4500-LB Need help with repair of PSU
Originally posted by dick_barton View PostThere are a number of fuses on the board which you have checked and were OK?
What dc voltages do you have across the 2 legs of each of the 3 long capacitors.
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Re: LG 42LW4500-LB Need help with repair of PSU
Check the forum using the search feature on how to test Psu.
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Re: LG 42LW4500-LB Need help with repair of PSU
Originally posted by dick_barton View PostThey are probably OK. Measure their ohmic value.
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Re: LG 42LW4500-LB Need help with repair of PSU
Originally posted by ReeceyBurger123 View PostThermistors should show short or low ohms, what voltage have you got on the main filter caps ?hte black thing under the gray capacitor is 230v plug
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Re: LG 42LW4500-LB Need help with repair of PSU
There are a number of fuses on the board which you have checked and were OK?
What dc voltages do you have across the 2 legs of each of the 3 long capacitors.Last edited by dick_barton; 11-19-2016, 09:46 AM.
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Re: LG 42LW4500-LB Need help with repair of PSU
They are probably OK. Measure their ohmic value.
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Re: LG 42LW4500-LB Need help with repair of PSU
Thermistors should show short or low ohms, what voltage have you got on the main filter caps ?
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LG 42LW4500-LB Need help with repair of PSU
Hi guys today my TV stops working (it woudnt turn on only led shine so the power goes into it) so i remove the back panel and unscrewed the PSU I checked the capacitors but all of them seems to bee good psychicaly I dont check their capacity if its good or not because no one of them is leaked after that i check whole board with my multimeter (PAN33D) and i found 2. suspicious components (it was thermistor) when i put + and - of my multimeter on it and multimeter was set to beep when he found short-circuit it beeps so I dissolder this 2 thermistors and do it again i again put + and - of my multimeter on their poles and it against beep so i think my TV wasnt start because this thermistors are in short-circuit (i read thermistor is for protecting whole board from short-circuit) So please can you help me ? I also need buy new but my local store doesnt have this one (I put photo in attach smaller one had DSC10D-9 printed on it and the bigger one had DSC-5D-15 120) if you dont understand me i will record a video on Youtube.Thanks for helpTags: None
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