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Equipment Repairs => LCD TV forum => Topic started by: kev1 on February 15, 2015,07:41:18

Title: LG55LA620V
Post by: kev1 on February 15, 2015,07:41:18
Can anyone help I have a LG55LA620V. comes on and screen goes of after a fwe seconds. is there anyway to check screen on this set. or shall I just replace psu.
Title: Re: LG55LA620V
Post by: Turnip on February 15, 2015,13:31:30
Hi Kev1,

Not yet met one - Is it Tube or Led lit ? and maybe some idea of panels to give a clue to the problem - Chris.
Title: Re: LG55LA620V
Post by: t1412 on February 16, 2015,14:26:16
in a dark room shine a torch on the screen bring the menu up, see if you can see it, if you can, the inverters could be in  trouble, check the voltages, also check for dry joints on the driver board. thanks

shaun
Title: Re: LG55LA620V
Post by: downunder on February 18, 2015,04:24:12

Hi Kev 1,

Can't be entirely sure, but I expect you have problems with the LED backlighting. Not aware of any test you

can do short of stripping down the panel. These usually suffer from bad joins between the various LED

strips inside the panel. If you do go down the strip road, you may need an extra person to help lift the 55'

panel off.....it's very brittle..             Bruce
Title: Re: LG55LA620V
Post by: kev1 on February 26, 2015,07:42:40
Changed psu and still the same .So stripped down screen swapped over the cable connectors on the power supply from the leds which started the set up. As one side has 4 led strips and the otherside has 3 strips.But a couple of leds look as if they are failing.
Also backlight is at 100% . When I powered up set it only ran for a short time so turned down backlight to 70% it ran for a couple of hours then turned it down to50% and ran OK . But still seems  to flicker slightly
So I would it looks like the default setting is at 100% which is oviously over driving the Leds.
Title: Re: LG55LA620V
Post by: downunder on February 26, 2015,14:09:20
 
So much for energy-saving LEDs!

Display panels are dying like flies.
Title: Re: LG55LA620V
Post by: Turnip on February 27, 2015,10:50:41
Hi Bruce and thanks for the heads up,

Hadn't realised led strips were arranged rather like tubes, always assumed a thick plastic sheet with leds at the top and bottom, maybe at the sides as well.

Glad it isn't the case as small screens don't smash so easy, and needed boards rarely turn up on the Flea.

Recall you recently chastised me for a spelling error, but guess Aussies just dye - Chris
Title: Re: LG55LA620V
Post by: downunder on February 28, 2015,04:09:08

Hi Chris,

Point taken, from the home of English vernacular, not that the flies would care.

On the education matter, LED TV are either edge lit (string of LEDs down each side) or array lit, where LEDs are uniformly located behind the viewing area.

Recently pulled one of the latter apart and turned it on. The light intensity almost blinded me. Had notion of
mounting it in my lounge room, but suspect SWMBO would not be impressed. - Bruce
Title: Re: LG55LA620V
Post by: Turnip on February 28, 2015,12:27:56
Hi Bruce, and thanks,

Not yet taken one apart but glad of array lit designs where if folks throw a RCU or whatnot and smash the screen, panels might be found on the Flea.

Small LED sets ever a problem, as top/bottom leds with a half inch thick plastic panel gives few boards for repair as folks can't easily break them.

Feel well educated, again  - Thanks - Chris