Samsung LCD TV LE40B750 flickering when turned on

[Mickymoody]

In LCD screens, I'd say, 90% the invertors (or stators in a traditional flo tube), would fail...but if the set was over say, 8 years old, the flo tube might be faulty.

But as the effect is random, a PSU fault. Low ESR, bulging caps, maybe.leaking electrolyte. Especially at startup. Hard to call.

 

[SHELDONSTV]

fault may still b power supply related but looking at yr video thats been uploaded its probably backlight failure- there is a circuit which is part of the invertor which monitors the current drawn to do with the backlights and any failure here will cause problems i am aware of a mod which can cure this fault ill have a look and see what i can find.......

 

[Mickymoody]

fault may still b power supply related but looking at yr video thats been uploaded its probably backlight failure- there is a circuit which is part of the invertor which monitors the current drawn to do with the backlights and any failure here will cause problems i am aware of a mod which can cure this fault ill have a look and see what i can find.......

But the fault resolves itself when warm, which would suggest primary PSU? But again, a fault in the primary, would cause severe problems. Hard call.

 

[zid336]

hi guys im new to here i also had the same fault my tV is just over 2 years old i rang samsung direct and was told to pay £108 pounds for a simple call out which i wasnt impressed about when the engineer come he advised me that after testing the TV that the power supply needed changing which would cost me £56.58pence...i explained to him that i wasnt happy that a TV or the spec i purchased starts having technical problems. A few days later the part arrived they come the same day and fitted the new power supply which had the newer type of capacitors on the board. i then decided to take up my case up with Samsung headoffice after writing a very deep email to them and told them of disappointment of my TV they contacted me directly and have offered to fully refund my money i paid to have my TV fixed im very pleased with the outcome. The engineer did advise me that this is a common fault across the range make your case heard to the manufacturer regardless if your TV is out warranty.

 

[Mickymoody]

That makes sense Zid, but not new type capacitors, just better rated ones. Low ESR, and higher voltage rated. The mains supply in this country is really poor, with constant brownout, or blackouts, I've had 8 rapid power on/offs in the last two weeks, which I suspect led to the condensor failing in my washing machine recently. My computer is protected by a surge protector, that has failed, and the latest outage caused my fiancees computer to not switch on on the front power switch, it needed unplugging first. These surges/dips are very bad for capacitors/ (condensors), and hence psu's.

Sounds like a relatively cheap fix Zid, but can't understand the high call out charge? Did they refund this against the part?

 

[zid336]

hi guys im not a wizz when it comes to all of the Technical stuff although the engineer that come out was a very sound bloke.. from what he told me the power supply board was more up to date and it had larger capacitors on the board.

Samsung UK are fully refunding the full amount including the call out and the cost of part so im happy with the outcome but thats only been done because of constant emailing to them with my dissatisfaction of their product.

Samsung know across the whole range their are manufacture faults the other one the engineer stated was the constant clicking some customers are experiencing.. so my advice is if it is within 3 years of age regardless iff the warranty has ran out get in touch with them hopefully commen sense will prevail.
thanks for all the helps guys great forum

 

[khalil]

Wow,

I was gobsmacked when I saw so many people have viewed my post.

I could manage to get a cover plan for the TV and I have already sent it out to be repaired for three times! The first time the main board was replaced, but the problem came back after few months...the second and third time the power supply to the TV was replaced...but the picture still flickers once the TV is turned on. Although the flickering is now just on the bottom half of the picture. I am 100% sure that the issue lies with the Backlight as when I turn the backlight to zero the flickering disappears.
This time I am sending the TV out for a write off, so I will hopefully be able to get a new TV.

NEVER A SAMSUNG AGAIN....NEVER

 

[err]

hallo there, I have the same tv and exactly the same flickering problem, its just that yesterday while I was watching the picture went black but the sound was still ok.I turned it off, then again on, watched for half a minute and then the picture gone just sound.Turned the tv off for 10 mins and everything seemed to be ok for 1hour and a half.could you locate the problem?thank you

 

[err]

any ideas?

 

[Sam Gangee]

could you locate the problem?

Whereabouts in Greece?

 

[err]

regarding my tv , athens by the way

 

[Alarm]

Strike action by the electricity board?

Sorry had to be done.

 

[err]

Strike action by the electricity board?

Sorry had to be done.

not quite

 

[Alarm]

Sounds like a cold solder joint. When it heats up it expands and looses connection.
Check the boards if you can.

 

[Sam Gangee]

regarding my tv , athens by the way

That's awkward. There's a bit of sea in the way. Still, if you want to bring it over to Crete I'll be here for another 3 weeks!

Kali tiXi.