LG 42LN5400 clicking sound when powered on

[Gadjet]

There is a red standby light, when you power it on it flashes and the tv makes a clicking sound. However there is never a picture that shows. I have disconnected the y sus from the power supply and the clicking doesn't happen and the red standby goes out after powering on but still no picture or backlight. also disconnected the x sus board and reconnected the y sus clicking returns no other changes.

[ReeceyBurger123]

Re: LG 42LN5400 clicking sound when powered on

The Tv in the images is not a 42LN5400 ? I repaired a few of these shorted fets on the Ysus. Do you have a DMM ?

[ReeceyBurger123]

Re: LG 42LN5400 clicking sound when powered on

The Z/Xsus kills the Ymain in these, the copper coils on the Zsus break through the solder joints which kills the Ymain.

[Gadjet]

Re: LG 42LN5400 clicking sound when powered on

Sorry your correct was looking at the wrong label, its a Zenith Z42PJ240

[Gadjet]

Re: LG 42LN5400 clicking sound when powered on

So should I replace both the Y and x/z?

[ReeceyBurger123]

Re: LG 42LN5400 clicking sound when powered on

No cheaper and more reliable to repair them easy to do, also you will get some experience. You have a DMM ?

[Gadjet]

Re: LG 42LN5400 clicking sound when powered on

yes i have one

[ReeceyBurger123]

Re: LG 42LN5400 clicking sound when powered on

Right do you know how to find S\C ?

[Alastair E]

Re: LG 42LN5400 clicking sound when powered on

It'll be the two on the small heatsink in the middle and the two on the left-hand heatsink near the bottom.

Usually caused by one of the small ceramic caps going short near bottom of l/h heatsink.

Ive had two of these, both with that blue cap cracked or blown to bits.....
1N 1kV disc ceramic

IF you Dont replace that cap, It may last an hour or a month--but sooner or later, Bang again!

[ReeceyBurger123]

Re: LG 42LN5400 clicking sound when powered on

It'll be the two on the small heatsink in the middle and the two on the left-hand heatsink near the bottom.

Usually caused by one of the small ceramic caps going short near bottom of l/h heatsink.

Ive had two of these, both with that blue cap cracked or blown to bits.....
1N 1kV disc ceramic

IF you Dont replace that cap, It may last an hour or a month--but sooner or later, Bang again!

Not in my experience, the 30J124 or 30F124 fets go S/C when the coils on the Zsus break through the solder the ones I repaired have been gone for ages now (over 4 months), never seen that cap blown but will take note buddy chees

[Alastair E]

Re: LG 42LN5400 clicking sound when powered on

Ive had a few fail like that. Sometimes the cap just cracks (The most 'dangerous') sometimes there's nothing left of it!
--Its the one directly opposite the bottom of the row of the wire end of the four elect-caps in centre of board.

Its best-case when the cap blows itself completely to oblivion--No chance of it ever shorting again.
--Its when it just cracks is when its sure to fail taking the four IGBT's and the 2.2 ohm with it....

This resistor is just by the Vs fuse on the board as I recall--Maybe the one near bottom--just check 'em, you'll know if its open, all you'll get on screen is a coloured mass of mal-discharge....

[ReeceyBurger123]

Re: LG 42LN5400 clicking sound when powered on

Hmm, I have seen repair kits that have a 2.2ohm resistor in them but the ones I had in to fix that resistor was fine, maybe a combination of problems that cause the Ysus to have a meltdown. Also I always see them 30F & 30J transistors randomly blowing on quite a few different Tvs seen it on Samsungs and Lgs quite often.

[Alastair E]

Re: LG 42LN5400 clicking sound when powered on

Usually used in the SUS_Up/SUS_Dn so are under a lot of stress.....

I bought a truckload of 'em!

[ReeceyBurger123]

Re: LG 42LN5400 clicking sound when powered on

Yep normally them that fail, I have also replaced alot. Good job they are cheap to obtain though.

[Gadjet]

Re: LG 42LN5400 clicking sound when powered on

not sure what s /c stands for?

[budm]

Re: LG 42LN5400 clicking sound when powered on

Short Circuit.

[Gadjet]

Re: LG 42LN5400 clicking sound when powered on

ok so i examined the board and this is what i found on the back of the ysus.