LG FLATRON not powering up - Page 1
Forum section: electronics / repair

author: giovani
author_rank: Newbie
timestamp: December 15, 2014, 04:41:24 pm
content: 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.

author: ElektronikLabor
author_rank: Regular Contributor
timestamp: December 15, 2014, 09:03:21 pm
content: Hello giovani,I found here a pic of the power supply board:PowerIf 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!)

author: giovani
author_rank: Newbie
timestamp: December 15, 2014, 09:11:59 pm
content: 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

author: wraper
author_rank: Unknown
timestamp: December 15, 2014, 09:15:14 pm
content: Probably capacitors on secondary side are dead. And checking power by making spark is umm... stupid?

author: giovani
author_rank: Newbie
timestamp: December 15, 2014, 09:21:00 pm
content: 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

author: giovani
author_rank: Newbie
timestamp: December 15, 2014, 09:23:42 pm
content: and only the blue one (450 V) i tried

author: wraper
author_rank: Unknown
timestamp: December 15, 2014, 09:43:34 pm
content: 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.

author: giovani
author_rank: Newbie
timestamp: December 16, 2014, 01:51:04 pm
content: 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

author: ElektronikLabor
author_rank: Regular Contributor
timestamp: December 16, 2014, 08:04:53 pm
content: Troubleshooting without tools is difficult, unless you measure voltages with your tongueIf 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.

author: giovani
author_rank: Newbie
timestamp: December 16, 2014, 08:51:04 pm
content: 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

author: tautech
author_rank: Super Contributor
timestamp: December 16, 2014, 08:58:35 pm
content: Quote from: giovani on December 16, 2014, 08:51:04 pmWithout 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.

author: wraper
author_rank: Unknown
timestamp: December 16, 2014, 09:00:28 pm
content: 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.