I just fixed another LG 47” by swapping bad diodes for good ones. I noticed a repair service when googling that claims to modify your LG power supply to stop it from overdriving the LEDs and burning them out. Does anyone happen to know the gist of what they're doing as I'd like to do the same. I don't like repairing and reselling these TVs knowing the same problem will most likely pop up again.
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Re: Modifying LG Power Supply to prevent overdriving LEDs?
im not sure on lgs this thread is regarding a vizio but may give you a idea on the mod
https://www.badcaps.net/forum/showth...ed+current+mod -
Re: Modifying LG Power Supply to prevent overdriving LEDs?
maybe a starting point would be the cooling,
i'v not seen a teardown yet that shows the led strips thermally coupled to the metalwork properly.Comment
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Re: Modifying LG Power Supply to prevent overdriving LEDs?
I have been pressing the strips back down and hot gluing the edges to keep them in place as well as creating some glue straps across the raised “pegs” that are used to keep the strips in the right place. As far as I can tell the cooling effectiveness should be factory. If the driver is driving them at a higher current than they’re rated for then the cooling won’t matter in the long run because they’ll still burn out. I noticed several diodes that were much dimmers than others when testing them with my multimeter so I can only assume they are next to fail as their resistance is increasing.Comment
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Re: Modifying LG Power Supply to prevent overdriving LEDs?
The LED PCB strip has no thermal VIA's to conduct the heat from the top layer to the bottom layer so the way it is right now the heat transfer from the top layer to the bottom layer is joke, and if they do add the VIA's then then will have to add electrical insulation between the strip and the metal chassis.Never 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: Modifying LG Power Supply to prevent overdriving LEDs?
i thought all the tv strips used aluminium pcb's??Comment
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Re: Modifying LG Power Supply to prevent overdriving LEDs?
It would have been nice but that costs more than just simple double sided copper clad board, they have to cut cost and make sure they go bad after the warranty runs out.Never 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: Modifying LG Power Supply to prevent overdriving LEDs?
Picked up another 47 and 55 tonight. Lot of these LGs with dead leds.Comment
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Re: Modifying LG Power Supply to prevent overdriving LEDs?
You may find them with badly burn out LED's:
https://www.badcaps.net/forum/showth...hlight=latw%2A
https://www.badcaps.net/forum/showth...ht=LG+47LN5790Never 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: Modifying LG Power Supply to prevent overdriving LEDs?
Just replaced one bad diode on the 55”. Time to put it back together. Gave the guy $40 for the TV last night. Alsways nice when a plan comes together. Lol. Now to do the same to the 47” to upgrade my bedroom tv.Attached FilesComment
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Re: Modifying LG Power Supply to prevent overdriving LEDs?
Just make sure to turn down the backlights level to as low as possible on ALL input settings.Never 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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Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.
Upon bringing it home and plugging it up, it showed a standby light.
I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.
The screen seems to blackout and stay black, but with a flashlight I can see the display.
With my Playstation 4 connected via HDMI, and running a game I can hear sound.
Assuming... -
I have wanting to do this project for quite sometime now and I finally found a switching power supply that will work on this desoldering gun station ZD-915 that the original switching power supply took a shit and just was not worth trying to fix it because this switching power is not quite big enough to handle the heater element and the vacuum pump
One note when I tested the switching power supply and the voltage control board I noticed that this desoldering gun heat up much faster than the original switching power supply which I was really surprised by to the point that I might buy... -
I have been working on this concept for quite some time now with limited success but recently I found a switching power supply that is setup for the voltage that this soldering station needs to operate at however it also needs part of the secondary circuit from the original switching power because you need several voltage rails
I once tried to get a ZD-915 desoldering station to work on a 18 volt battery power supply but unfortunately things did not go well but I did find a work around but I might try this idea again but going at a little differently more about this another time... -
Hi all, I just need to know that, can i use SMPS type power supply to test and short circuit detection on a laptop motherboard?
I saw 95% of repair guys are using only Linear bench power supply. linear bench power supply is pricy, thats why i planned to get one SMPS supply.
i know that in linear power supply the noise will be very low comparing to SMPS supply.... -
Hello Everybody,
Trying to repair a power supply from a Russound CA4 Multizone Controller (picture attached)
Russound no longer supports it but were kind enough to provide a schematic of the power supply (pdf attached).
The outputs marked 12v and 20v are all measuring only 1v.
The board is clicking, which I think means it is in something called hiccup mode when the flyback transformers switches because of an internal problem or something else on the board Overloading it.
The capacitors physically look clean (no bludgesor leaks) and...
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