Badcaps.net Forum
Go Back   Badcaps Forums > Troubleshooting Hardware & Devices and Electronics Theory > Troubleshooting TVs and Video Sources
Register FAQ Calendar Search Today's Posts Mark Forums Read

 
Thread Tools Display Modes
Old 12-12-2018, 03:54 AM   #1
Amraks
Badcaps Veteran
 
Join Date: Nov 2011
City & State: Tasmania
My Country: Australia
Line Voltage: 230VAC
I'm a: Knowledge Seeker
Posts: 593
Default Sasmung la40m81bd - Recapped

History:
PSU only recapped.
This TV was not turning on a few weeks ago I then recapped it as I recall I swapped all capacitors except a 163v 1uf as I didn't have this value.
A few weeks pass.
The TV now is coming back to me with with a picture fault.
https://youtu.be/sYJE7VpX4yE
Any idea what may cause this? could it be that 163v 1uf I didn't recap?

Just want this customer to have their tv back as I have their other one at the moment as well.

Last edited by Amraks; 12-12-2018 at 05:00 AM..
Amraks is offline   Reply With Quote
Old 12-12-2018, 04:24 AM   #2
Hamie
Badcaps Veteran
 
Hamie's Avatar
 
Join Date: Apr 2014
City & State: Scotland
My Country: UK
I'm a: Forum Junkie
Posts: 1,314
Default Re: Sasmung la40m81bd - Recapped

Try heating the main board metal shield. If the picture comes back then it's probably the 2 x 1000uf caps under the tin work.
Hamie is offline   Reply With Quote
Old 12-12-2018, 04:51 AM   #3
Amraks
Badcaps Veteran
 
Join Date: Nov 2011
City & State: Tasmania
My Country: Australia
Line Voltage: 230VAC
I'm a: Knowledge Seeker
Posts: 593
Default Re: Sasmung la40m81bd - Recapped

They where replaced though with new ones. forget which brand I used for them.
Ill check their ESR when it comes back.

Any idea what the 1uf 163v would do?
Amraks is offline   Reply With Quote
Old 12-12-2018, 04:54 AM   #4
Amraks
Badcaps Veteran
 
Join Date: Nov 2011
City & State: Tasmania
My Country: Australia
Line Voltage: 230VAC
I'm a: Knowledge Seeker
Posts: 593
Default Re: Sasmung la40m81bd - Recapped

Oh Oops just noticed you meant the mainboard I originally recapped the PSU board.
Amraks is offline   Reply With Quote
Old 12-12-2018, 05:48 AM   #5
drussell
Senior Member
 
Join Date: Nov 2014
City & State: Calgary, AB
My Country: Canada
Line Voltage: 120/240V, 60 Hz
I'm a: Hardcore Geek
Posts: 139
Default Re: Sasmung la40m81bd - Recapped

Just a quick aside... There is no such thing as a 163 volt capacitor rating. 63? Yes. 100? Sure. 150 or 200? Yup...

Even 160 and 165 are something that (while rare), do actually exist but I've never seen a 163 volt capacitor.
drussell is offline   Reply With Quote
Old 12-17-2018, 05:32 PM   #6
Amraks
Badcaps Veteran
 
Join Date: Nov 2011
City & State: Tasmania
My Country: Australia
Line Voltage: 230VAC
I'm a: Knowledge Seeker
Posts: 593
Default Re: Sasmung la40m81bd - Recapped

its a 160v not sure how I got 163v.

I can not see how it could be a cap on the mainboard as they are smd

Last edited by Amraks; 12-17-2018 at 05:49 PM..
Amraks is offline   Reply With Quote
Old 12-17-2018, 07:25 PM   #7
nomoresonys
Badcaps Veteran
 
Join Date: Jan 2013
City & State: midwest
My Country: U.S.
I'm a: Knowledge Seeker
Posts: 3,216
Default Re: Sasmung la40m81bd - Recapped

Video resembles a tcon problem?
nomoresonys is offline   Reply With Quote
Old 12-17-2018, 08:59 PM   #8
Amraks
Badcaps Veteran
 
Join Date: Nov 2011
City & State: Tasmania
My Country: Australia
Line Voltage: 230VAC
I'm a: Knowledge Seeker
Posts: 593
Default Re: Sasmung la40m81bd - Recapped

Heres a better video now I have the tv in my hands.
https://youtu.be/d3zCpfB23Sg
Amraks is offline   Reply With Quote
Old 12-17-2018, 09:05 PM   #9
budm
Badcaps Veteran
 
budm's Avatar
 
Join Date: Feb 2010
City & State: S.F. Bay area
My Country: USA
Line Voltage: 120V 60Hz
I'm a: Knowledge Seeker
Posts: 35,473
Default Re: Sasmung la40m81bd - Recapped

Quote:
Originally Posted by Amraks View Post
its a 160v not sure how I got 163v.

I can not see how it could be a cap on the mainboard as they are smd
What do you mean by ' how it could be a cap on the main board as they are SMD'? SMD is just a form factor, so if it is SMD lytics cap then they can still fail just like other lytics caps.
__________________
Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956

Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999

Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl

Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/

TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
budm is online now   Reply With Quote
Old 12-17-2018, 09:12 PM   #10
Amraks
Badcaps Veteran
 
Join Date: Nov 2011
City & State: Tasmania
My Country: Australia
Line Voltage: 230VAC
I'm a: Knowledge Seeker
Posts: 593
Default Re: Sasmung la40m81bd - Recapped

I thought they where rare to fail budm.
Amraks is offline   Reply With Quote
Old 12-17-2018, 09:23 PM   #11
nomoresonys
Badcaps Veteran
 
Join Date: Jan 2013
City & State: midwest
My Country: U.S.
I'm a: Knowledge Seeker
Posts: 3,216
Default Re: Sasmung la40m81bd - Recapped

Try heating things with a hairdryer on the mainboard and tcon, see if picture changes and maybe the one ribbon at a time tcon check.
nomoresonys is offline   Reply With Quote
Old 12-17-2018, 09:56 PM   #12
Amraks
Badcaps Veteran
 
Join Date: Nov 2011
City & State: Tasmania
My Country: Australia
Line Voltage: 230VAC
I'm a: Knowledge Seeker
Posts: 593
Default Re: Sasmung la40m81bd - Recapped

I checked both sides of the tcon left and right, left side pulled was white with right side still showing this defect.
right side pulled was the same as well but opposite.

heated up around the main-board and tcon the problem doesn't go away.
Amraks is offline   Reply With Quote
Old 12-17-2018, 10:10 PM   #13
nomoresonys
Badcaps Veteran
 
Join Date: Jan 2013
City & State: midwest
My Country: U.S.
I'm a: Knowledge Seeker
Posts: 3,216
Default Re: Sasmung la40m81bd - Recapped

Check the capacitors on the tcon for shorts, tv unplugged, meter in diode mode.

Last edited by nomoresonys; 12-17-2018 at 10:11 PM..
nomoresonys is offline   Reply With Quote
Old 12-17-2018, 10:32 PM   #14
Amraks
Badcaps Veteran
 
Join Date: Nov 2011
City & State: Tasmania
My Country: Australia
Line Voltage: 230VAC
I'm a: Knowledge Seeker
Posts: 593
Default Re: Sasmung la40m81bd - Recapped

checked all caps for shorts on the tcon board couldn't find any shorted
Amraks is offline   Reply With Quote
Old 12-17-2018, 11:14 PM   #15
Amraks
Badcaps Veteran
 
Join Date: Nov 2011
City & State: Tasmania
My Country: Australia
Line Voltage: 230VAC
I'm a: Knowledge Seeker
Posts: 593
Default Re: Sasmung la40m81bd - Recapped

I replaced that cap on psu that I didn't have before problem is still there.
Amraks is offline   Reply With Quote
Old 12-18-2018, 06:59 AM   #16
nomoresonys
Badcaps Veteran
 
Join Date: Jan 2013
City & State: midwest
My Country: U.S.
I'm a: Knowledge Seeker
Posts: 3,216
Default Re: Sasmung la40m81bd - Recapped

Maybe test the voltage regulators on mainboard, tutorial if needed in budm's signature post #9.

Last edited by nomoresonys; 12-18-2018 at 07:02 AM..
nomoresonys is offline   Reply With Quote
Old 12-18-2018, 07:22 AM   #17
Dannyx
CertifiedAxhole
 
Dannyx's Avatar
 
Join Date: Aug 2016
City & State: Constanta
My Country: Romania
Line Voltage: 230VAC 50Hz
I'm a: Hardcore Geek
Posts: 2,396
Default Re: Sasmung la40m81bd - Recapped

I believe you removed the video.

I'm just going to give my 2 cents nonetheless by saying it's probably a T-con issue since you're saying both sides of the screen display the same. Ideally, you'd have a second main board/T-con to compare how each performs.

Do some measurements on the t-con board: there should be test points labeled VCC, 1.2v, VGH, VGL, etc. Really curious to see how this telly gets fixed
__________________
Wattevah...
Dannyx is offline   Reply With Quote
Old 12-19-2018, 08:45 PM   #18
Amraks
Badcaps Veteran
 
Join Date: Nov 2011
City & State: Tasmania
My Country: Australia
Line Voltage: 230VAC
I'm a: Knowledge Seeker
Posts: 593
Default Re: Sasmung la40m81bd - Recapped

Here is a photo of the tcon all the VCC lines seem to match their values I can't find vgh or vgl
Attached Images
File Type: jpg IMG_20181220_143548.jpg (1.17 MB, 11 views)
Amraks is offline   Reply With Quote
Old 12-19-2018, 09:02 PM   #19
budm
Badcaps Veteran
 
budm's Avatar
 
Join Date: Feb 2010
City & State: S.F. Bay area
My Country: USA
Line Voltage: 120V 60Hz
I'm a: Knowledge Seeker
Posts: 35,473
Default Re: Sasmung la40m81bd - Recapped

How about AVDD, AVDD_1, VDD around the left side of the board around IC8?
You can also look up the spec sheet of that IC8 TPS65160A to see how many output Voltage sources it has.
budm is online now   Reply With Quote
Old 12-19-2018, 09:15 PM   #20
Amraks
Badcaps Veteran
 
Join Date: Nov 2011
City & State: Tasmania
My Country: Australia
Line Voltage: 230VAC
I'm a: Knowledge Seeker
Posts: 593
Default Re: Sasmung la40m81bd - Recapped

Some more photos
Attached Images
File Type: jpg IMG_20181220_151142.jpg (1.24 MB, 10 views)
File Type: jpg IMG_20181220_151247.jpg (927.4 KB, 4 views)
Amraks is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



Badcaps.net Technical Forums 2003 - 2019
Powered by vBulletin ®
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
All times are GMT -6. The time now is 12:03 AM.
Did you find this forum helpful?