Author Topic: LG FLATRON not powering up  (Read 6156 times)

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Offline giovaniTopic starter

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LG FLATRON not powering up
« on: December 15, 2014, 04:41:24 pm »
Hi i have a LG Flatron w2234s and when i plug it in in doesn't want to power up at all i opened it doesn't seen burnt inside , or the power supply. I shorted out the capacitors and they were charged so it mean that it gets power the LED in front doesn't turn on either. If anyone can help.
 

Offline ElektronikLabor

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Re: LG FLATRON not powering up
« Reply #1 on: December 15, 2014, 09:03:21 pm »
Hello giovani,
I found here a pic of the power supply board: Power

If you have the right equipment:

* Measure if the fuse is blown (continuity). It's upper right from the mains connector (white ceramic tube)

* In the corner top right there is an connector: measure the voltages of the pins.

* What is the whole power consumption of the Display?

* On the mainboard: Is something getting hot? (be careful if you are going to touch something!)
 

Offline giovaniTopic starter

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Re: LG FLATRON not powering up
« Reply #2 on: December 15, 2014, 09:11:59 pm »
the fuse is ok because the capacitor is charging always i will have to open it again to check the pins and the whole power consumption i dont know it  but thank you anyways
 

Offline wraper

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Re: LG FLATRON not powering up
« Reply #3 on: December 15, 2014, 09:15:14 pm »
Probably capacitors on secondary side are dead. And checking power by making spark is umm... stupid?
 

Offline giovaniTopic starter

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Re: LG FLATRON not powering up
« Reply #4 on: December 15, 2014, 09:21:00 pm »
i just tried it with a screwdriver i wasn't sure if it was charged so i shorted it out before touching anything on the board
 

Offline giovaniTopic starter

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Re: LG FLATRON not powering up
« Reply #5 on: December 15, 2014, 09:23:42 pm »
and only the blue one (450 V) i tried
 

Offline wraper

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Re: LG FLATRON not powering up
« Reply #6 on: December 15, 2014, 09:43:34 pm »
Look if there are electrolytic capacitors with bulging top on secondary side. If there are any Capxon or Samxon GF series (green color), then likely they are dead. Samwha WB are no good too.
 

Offline giovaniTopic starter

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Re: LG FLATRON not powering up
« Reply #7 on: December 16, 2014, 01:51:04 pm »
i checked the caps they seem to be fine they and they are made by Su'scon here are some photots of the power supply
 

Offline ElektronikLabor

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Re: LG FLATRON not powering up
« Reply #8 on: December 16, 2014, 08:04:53 pm »
Troubleshooting without tools is difficult, unless you measure voltages with your tongue ;)

If the blue cap is charged, than the primary side should be ok; try to find out if the secondary side is ok.
If you don't have any Multimeter, you can short the caps with a screwdriver; shortly after the Board was switched off!
It's stress for the caps if they are discharged by a short, but it should't damage them if you do it only a few times.
 

Offline giovaniTopic starter

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Re: LG FLATRON not powering up
« Reply #9 on: December 16, 2014, 08:51:04 pm »
i do have multimeter but i am not sure if its working properly (its closing by it self it might be the battery i havent use it in like half of year) so where should i check the voltages at the wires or to check every cap
 

Offline tautech

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Re: LG FLATRON not powering up
« Reply #10 on: December 16, 2014, 08:58:35 pm »
i do have multimeter but i am not sure if its working properly (its closing by it self it might be the battery i havent use it in like half of year) so where should i check the voltages at the wires or to check every cap
Without good tools and knowlegde/experience of SMPS, I suggest you look for a replacement PCB on eBay.
You will be unlikely to fix this with only a DMM.
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Siglent Youtube channel: https://www.youtube.com/@SiglentVideo/videos
 

Offline wraper

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Re: LG FLATRON not powering up
« Reply #11 on: December 16, 2014, 09:00:28 pm »
Su'scon is utter crap too. Not widely used in monitors though. Often there can be found cemetery of them in Routers and satellite tuners. Fact they are not bulging do not mean that they are ok. This is working like bulging cap is a dead giveaway that it failed but not other way.
 


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