Samsung LCD TV Flickering and crackling

[dazza]

I have a couple of Samsung LCD TVs > 8 years old.

One i've replaced the capacitors on the power board 3 times as it keeps failing to switch on or if it does switch on it switches off shortly after. This tv is currently working as expected.

The other TV has started flickering when it flickers is makes a crackling noise.

Could this be an easy fix? Should i whip it apart and look for any bulged capacitors?

Thanks as always for any help/advice

 

[Seadog]

Take it apart and have a look. Capacitors are a major source of faults. However, replacing them three times seems excessive. Are you using decent quality low ESR components or just cheap Chinese ones?

 

[123hotchef]

poxy tvs they design them to do that

 

[dazza]

Take it apart and have a look. Capacitors are a major source of faults. However, replacing them three times seems excessive. Are you using decent quality low ESR components or just cheap Chinese ones?

I bought the components from a local place they seem to have good quality stuff. They lasted longer than the original samsung ones.

poxy tvs they design them to do that

The TV was one month out of warranty the first time it happened.

 

[123hotchef]

they get people to work out what components will fail they know what ones will last it has a name i forget what they call it

 

[MattF]

Planned obsolescence. It is, IMHO, a common myth in most cases.

If it's crackling, I'd be checking for dry joints or any signs of arcing/carbonisation, first off.

 

[123hotchef]

Planned obsolescence. It is, IMHO, a common myth in most cases.

If it's crackling, I'd be checking for dry joints or any signs of arcing/carbonisation, first off.

oh its real trust me a guy i went to school with was involved in changing designs of stuff for fords so it went wrong aint spoke to him for years though

 

[rikrobson]

It's going to have to be taken apart. You may as well get ne caps anyway. Look for dry joints or resolder

 

[dazza]

Had a good look over the power board, nothing really stands out.

Started taking the caps off (the same bunch that had problems on the other tv) but they all seem ok testing with Capacitance Meter.

Not sure how accurate it is.

https://www.amazon.co.uk/gp/product/B009CSR8BA/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

 

[Seadog]

It's probably accurate enough to give an indication of a good or bad cap, I've a similar one myself. The problem is that characteristics change with temperature, generally that will make itself evident with a bulging can.

 

[dazza]

There are a couple of second hand boards available on eBay. Is it worth a try?

 

[dazza]

So the broken tv was switched out with one that had been sitting in the garage for a year since i switched the bad caps. Two weeks of use and its started switching off again .

 

[Rocketman]

You sure it's not a problem that the small caps are eating the board. Any green around where the bad caps were?

 

[dazza]

You sure it's not a problem that the small caps are eating the board. Any green around where the bad caps were?

Will have a look tomorrow. Will also check the caps i put in i probably have a dry joint.

 

[WorkshopChris]

Do you have any photos. was wondering if the cracking was a breakdown of the power supply letting higher voltage through that could account for the caps dying prematurely.

 

[dazza]

Do you have any photos. was wondering if the cracking was a breakdown of the power supply letting higher voltage through that could account for the caps dying prematurely.

Given up on the TV with the crackling for now (Never replaced any caps everything is original).

Its the other TV with the bad power supply caps. Switches to standby.

 

[dazza]

Bought a seller refurbished PSU from eBay. Think its worse than the one in there the tv powers on but no picture.

From what i've read online other people have changed or reset the eeprom but surely if that was knackered it would not switch on with the original board also?

 

[ChrisJ]

oh its real trust me a guy i went to school with was involved in changing designs of stuff for fords so it went wrong aint spoke to him for years though

I have a old school friend who works for a leading car UK manufacturer, when they test the cars and find a component that is likely to and does fail, they have a big meeting with the bosses and they decide whether it is cost effective to recall all the vehicles affected or just let them fail, shocked me I can tell you.

 

[dazza]

Just been looking online TV's are much cheaper these days, may as well give up and buy something cheap.

Any recommendations? 40"

 

[the snooper]

I've not read the full thread but what type of back light if it's cold cathode tube look at the invertor