Can caps cause lcd image retention?

[gordesky1]

My friend gave me a olevia 242tfhd cause he bought a 50inch tv on black Friday, He said it didn't turn on so i took it apart and behold there was about 5 bad caps on the psu, So i switch them out with radio shack ones that look like blue and ony 85c instead of 105c and the old ones was 105 and 35v 560uf vs the radio shack 85c 35v 1000uf.. ...Yea i know its best to order the best ones online..

But at the time i couldn't order online for other reasons, So i figure i give the radio shack ones a try, So i pop them in and everything turns on and works perfect!!! So for the pass week i been using this tv as a monitor for my computer.

And wow this screen does have a really nice pic and bright so im loving it, But i been noticing alot of image burn in which is image retention for lcds. It gets it alot like if i leave it on desktop for i say about 5 to 10mins you can see the icons still on dark colors like greys.. pretty much anything that doesn't move it will show it for a bit..

It does go away tho if i put a white screen up or play something with movement or even turning it off for awhile.

So i was wondering can using the wrong caps cause this issue? i always herd you can use higher voltage and higher uf than the old cap. I mean everything is working as it should but this is the first lcd i ever had this much image retention.

Ony lcd i experience it with but not as bad is my old 2007 dell 20.1w ips monitor which is like 8 years old now and has about 70k hours on the clock. But i just took it because its just ageing.

Thanks

[budm]

Re: Can caps cause lcd image retention?

Since the caps from Radio Shack that you put in are general purpose type not low ESR/Impedance type, then you should put in the correct type and see. General purpose type may last days or months.

[retiredcaps]

Re: Can caps cause lcd image retention?

And wow this screen does have a really nice pic and bright so im loving it,

I find most TV default settings are set to maximum brightness to "wow" the consumer. Everything I have at home including my lcd computer monitors are set to much lower contrast and brightness settings.

By using this TV with probable default settings has a computer monitor, it does not surprise me to hear about image retention.

edit: The 85C Radio Shack caps won't last long. As budm said, it may last days or months. They are not the right type of caps (you need low ESR caps) and the 85C rating means the caps won't last nearly as long as 105C caps.

Every 10C increase in temperature decreases the lifespan of the capacitor by 50%. Conversely, for every 10C decrease in temp, lifespan increases by 2x. To make this crystal clear ...

A 85C cap rated for 1000 hours implies

85C = 1000 hours
75C = 2000 hours
65C = 4000 hours
55C = 8000 hours

A 105C cap rated for 1000 hours implies

105C = 1000 hours
95C = 2000 hours
85C = 4000 hours
75C = 8000 hours
65C = 16,000 hours
55C = 32,000 hours

As you can see, ordering the correct caps can increase the lifespan roughly by 24,000 hours, almost 3 years if running 24x7, if the TV runs around 55C internally. Some caps might run hotter than 55C if they are near high power transistors or IC/heatsinks.

In addition, only replacing the obviously bloated caps is another mistake most newbies make. Think cockroach theory or guilty by association. If there were 5 bad caps on the PSU and the other remaining non bloated caps are the same model and series, they are automatically suspect (cockroach or guilty by association).

I can see how people make that mistake, because the first search result that comes back is 2.5 minute youtube video

https://www.youtube.com/watch?v=PN-H79Rbv1g

and the person there only replaced the 2 obviously bloated capacitors. He didn't say with what and I highly doubt he tested the other capacitors out of circuit with an ESR tester.

For a channel called "After Hours Tv & Pc repair", I expect better advice.

[retiredcaps]

Re: Can caps cause lcd image retention?

@budm,

Do you have access to a thermal imager like Flir One or equivalent?

It would be interesting to see what the internal temperature of a "typical" TV is and see the temperature differences between caps standing alone and caps near big heatsinks.

The 55C number was just a guesstimate on my part.

[gordesky1]

Re: Can caps cause lcd image retention?

I guess i will see how long these caps will last, But i probably will replace them with the good caps soon maybe ordering from badcaps. Tho i do see some people having luck with these caps and had them in their tv over a year from googleing.

I knew these were the wrong ones to buy but got them cheap, Now when i asked for low esr caps they grab these ones and said they are the low esr ones. So than after i open them all i than notice it ony says 85c on the package... But like i said people used the same caps and had no problems yet.

And for the other caps there was ony 5 caps in that area which was the bad ones. So im sure the other ones are fine And they also not capxon/crapxon branded caps like the 5 ones i replaced hehe

And for the brightness and contrast i always lower those when i get my monitors/tvs, I never use the defaults. tv still looks great.

This tv to me just seems to get really bad with image retention no matter the settings, I have other lcd tvs which i also used as a monitor and i never got image retention. So maybe its because of age because i don't know the background story of this tv either. Or maybe its the caps causing it.

But is it really possible that these caps are causing this issue? Cause when looking this issue up for olevia it does seem like other people are having a issue like this so maybe its just olevia problem?

I would think i be having alot of other issues also if it was cause by the caps.

[nomoresonys]

Re: Can caps cause lcd image retention?

there might be some settings in the tvs service menu for that but you have to be very careful in there, it's easy to mess things up if you don't do them just right.