Author Topic: Samsung Series 5 40inch vertical lines and blocks across entire screen  (Read 4382 times)

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Offline maatsche

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Hi folks,


When looking for a solution on how to fix my TV I stumbled across the EEVblog YouTube channel.


I watched a few videos on the EEVblog YouTube channel trying to identify the fault but so far no luck...  :(


Im still trying to fix my Samsung TV and was hoping to get some guidance on where to look for the fault.

Last night when I played around with my Wii, which is connected via RCA,  I started to get strange blocks / lines  on my screen.

It just happened  from one second to another.

Initially I found that the Wii has had it but when switching over to HDMI I saw the issue to continue.

I realized the fault also to appear when no device is connected as I can see the picture issues also in the TV’s menu and so on and so forth.

Also restarting the TV didn’t do the trick.


I have taken the TV apart and checked all the caps on the PSU and other boards but couldn’t identify anything bloated or leaking.

Amazingly after putting everything back together and reconnecting the TV the fault didn’t show for approx. 5-10 seconds.

Then it showed some lines which disappeared again for a for a few seconds and then came back, until they stayed on the screen the entire time the unit was powered up.

I have attached some photos of the problem and was hoping you could point me in the right direction.

Even though the TV is quite old I would love to fix it as I am also not currently in the financial position to buy a new TV.


High Res images and a short video clip showing the fault appearing here:
https://www.dropbox.com/sh/r9rgjudvinsbk7h/AAB0j0vpZdrbW1foICubNgR8a?dl=0



Any help is highly appreciated.



Best regards,
Marcel
 

Offline saturation

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The videos are most important, the static images won't help.  Fault looks like its in the output stage as it occurs regardless of source you select.  As it appears transient my bet is on a loose connector or a decode glitch in the buffer area rather than hardware, aka decoder or driver type, failure.

Turning modern TVs off/on will not help, you need to do a system reset.  It varies from model and maker, so check you manual.  Its easiest to do first.

If that does not work, reopen the TV, and verify connections between all connectors/cables your see, if any click into place, loose cable is high suspect.  If that doesn't work, reseat them: disconnect then reconnect each.
« Last Edit: April 11, 2015, 01:14:37 pm by saturation »
Best Wishes,

 Saturation
 

Offline maatsche

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Thanks for your reply.

As suggested I have started with a factory reset via the service menu.

This didn't solve the problem.

The I moved on opened the TV up again and checked for any loose connectors/cables.

Everything was sitting solid in place.


As suggested I then disconnected everything cables boards, etc and disconnect then reconnect each cable.

I still have the same result as shown in the video on Dropbox (link in first post).


Is there anything else I can try to determine where the fault is coming from ?


Every help Is appreciated.



Best regards,
Marcel
 

Offline tec5c

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1 of 3 things is to blame here (out of a total of about 4 things that make up a TV these days! :P). The main pcb (the green board in picture 1 on the dropbox page you linked), the T-con pcb (it has the orangey ribbon cable going to it and is secured under a metal shield at the top of the TV), or the panel itself (this cannot be repaired).

I would be very, very surprised if it was the SMPS pcb (power supply) that was the problem.

Fault finding a main pcb or t-con pcb is quite complex and there's never an obvious place to begin.

I assume you don't have any warranty left on the TV as you wouldn't be here if there was.

It is a bit of a gamble but you can usually buy replacement pcb's online. Of course there is always the risk of; a) taking a "shot in the dark" and guessing which pcb to buy, b) buying both and then selling the other if you are successful with the repair or c) (worst case scenario) you buy both pcb's and the fault is still there.

Otherwise you could take it to a repair centre and see what they have to say about it.

Sorry I can't help more, they don't make TV's like they used to!
 

Offline Shock

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Please list in detail the equipment you have to diagnose and repair the TV, your electronics experience and also the exact model of the TV.




Soldering/Rework: Pace ADS200, Pace MBT350
Multimeters: Fluke 87V, 117, 27/FM     >>> Fluke 51/52 Thermometer Parts Required <<<
Oszilloskopen: Rigol DS1054Z, Phillips PM3065
 

Offline tom66

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Exact model number of the TV?
You can enter the service menu and check test patterns. Some Samsung sets generate test patterns separately on the main board or T-con which can help narrow down the cause.

To do this put the TV in standby, then
for USA/Canada model press MUTE 1 8 2 POWER in sequence on the remote
for Europe/Russia model press INFO MENU MUTE POWER in sequence on the remote

Test patterns are usually under "SVC" or "Control"
Do not touch any other values in service menu, you could break something...

 

Offline saturation

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It maybe worth your while to consider professional service at this point. 

One last simple item is to use sensitive thermometer or IR thermometer and check the quiescent operating temperature of all driver ICs.  They tend to kept near the same operating temperature, about 50-80C.  If it has failed completely, it will be cold, unlikely.  If its failing, it could run hotter than others.  You can then try cooling the specifically hot IC and see if it improves the picture.  Alas, failures can occur where such a simple test will not diagnose the issue.

As another mentioned, the T-CON aka timer controller board, is often to blame but not in all models.  You can try googling a specific model as often a specific failure is often well discussed.  Here is one with common failures and some easy troubleshooting techniques, some of which we discussed.  One possibility I missed is the cable could be bad see the link:

http://electronicshelponline.blogspot.com/2013/06/how-to-diagnose-failed-tcon-board-how.html

Good luck!
Best Wishes,

 Saturation
 

Online Rasz

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Fixed few TVs with same fault, its tin whiskers/cracked joints under ram chip.
Your first dropbox photo - next to heatsinked chip are two BGA chips, those are rams.

turn off TV, put your fingers on both of them and press ~gently (hard to tell, needs experience :)), turn on TV, wait 30 seconds, if picture is still ok let go of the ram chips, it should go back to shit. If you are not lucky this didnt work, repeat again pressing heatsink instead.

if its ram
3-5 year fix: splash flux around BGA chips, use hotair gun to reflow
permanent fix: desolder both,  clear shitty rohs solder from the chip and pads, put new pb balls on rams, solder back on

if pressing heatsink worked do the previous fix on it

if pressing didnt do anything its main scaler chip and you are effed, they usually go bad internally. In this case you can but one of those
http://www.banggood.com/Universal-LCD-TV-Controller-Board-VGAHDMIAVTVUSB-Interface-p-936100.html
and ghetto fix that TV :)
« Last Edit: April 22, 2015, 12:12:15 pm by Rasz »
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