Author Topic: LG 27LC2R LC TV Power Supply blowing the board fuse  (Read 1975 times)

0 Members and 1 Guest are viewing this topic.

Offline Gsimon850Topic starter

  • Newbie
  • Posts: 2
  • Country: gb
LG 27LC2R LC TV Power Supply blowing the board fuse
« on: May 01, 2018, 09:05:35 pm »
Hello chaps this is my first post so please be kind.

My nippers TV is blowing the power supply board 5Amp fuse, I am not an electronics engineer but i do have a basic knowledge of components very basic to be said.

I have found that the bridge rectifier is buggered this is a given, I have also tested the other diodes on the board and they all check out fine, and none of the caps are blown or swelling pointing to them. but on the hot side of the board there is one another diode that reads 0.124V in both directions.
Is this buggered I have never had a reading like this before from a diode in circuit and I don't know if another component could cause this (WTF) reading without removing the diode which I don't really want to do at the moment because really what the hell is this.
I only have a multimeter and I know you have to remove caps out of circuit to test them, hopefully that's correct.

Can you give me a pointer nothing is burnt on the board i have tested all the underside SMD resistors and alike. Like I said I am a noob but not totally thick just stumped and confused.
The bridge rectifier is on order X10 from Ebay and I have not got them yet but the other diode has thrown me a curve ball do I need to purchase this one as well. problem is I don't have the schematics for the borad and i am shooting in the dark and determined to sort it out, like dog with a bone, lol.
Many thanks upfront really appreciate your advice and time.
Take care chaps
Simon
 

Offline picandmix

  • Frequent Contributor
  • **
  • Posts: 395
  • Country: gb
Re: LG 27LC2R LC TV Power Supply blowing the board fuse
« Reply #1 on: May 02, 2018, 08:03:24 pm »



Hi,

Its not unusual for the fault to be just the diode block, they can overheat easily if their spec is minimal, often turning the solder joints dry or even burning the pcb with the heat generated.

Be wary of the electro caps as they can retain a powerful charge long after the power has been removed that can give you a nasty shock and burn  !








 

Offline lordvader88

  • Frequent Contributor
  • **
  • !
  • Posts: 935
  • Country: ca
Re: LG 27LC2R LC TV Power Supply blowing the board fuse
« Reply #2 on: May 03, 2018, 02:04:14 am »
Is this the PCB ? (I'm looking at google images)
https://spares2repair.co.uk/images/lg/LG%2027LC2R-ZJ%20-%20PSU%20-%20LGP2637N%20-%206709900016A%20-%2068709D0006B%20-%20REV%201.1%20-%20051202.jpg

There's are high current diodes that have a forward voltage drop of few 10s-100s of mV at the current a DMM would test it with.

Wish I had more stuff to try fixing, it's like a mystery video game only in real life.
 

Offline Gsimon850Topic starter

  • Newbie
  • Posts: 2
  • Country: gb
Re: LG 27LC2R LC TV Power Supply blowing the board fuse
« Reply #3 on: May 09, 2018, 05:35:41 pm »
Hi
Yes this is the very same board dude.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf