Announcement

Collapse
No announcement yet.

User Profile

Collapse

Profile Sidebar

Collapse
Avatar
magnusbjork
Member
Last Activity: 01-18-2013, 04:13 PM
Joined: 11-17-2012
Location: Echenevex
  •  
  • Filter
  • Time
  • Show
  • Source
Clear All
new posts
  • magnusbjork
    replied to Samsung LCD heat problem...?
    in Troubleshooting TVs and Video Sources
    Re: Samsung LCD heat problem...?

    Dear all,

    After fixing it my TV has now been working without any problem for weeks!

    Thanks a lot to all for your help! In the end the problem did indeed turn out to be the T-con board. I'm guessing that probably there's (at least) one bad solder connection between the CPU and the board. (?) ...But since I found a cheap-ish replacement board from eBay, -thanks for the link-, I just went ahead and bought one from there to try.

    Well, board installed, and all is back to normal, the picture stays perfect,...
    See more | Go to post

    Leave a comment:

  • magnusbjork
    replied to Samsung LCD heat problem...?
    in Troubleshooting TVs and Video Sources
    Re: Samsung LCD heat problem...?

    Gurus,

    I have found the place where the problem comes from.

    Have a look at the two pictures attached, one is a general view of the rear of the TV, without the metal cover over the "display card" (?). The other picture shows the "display card". On this "display card" I found that the CPU (?) was getting quite hot. (The big IC with the heat transfer "rubber" attached.) If I heated this one gently with my heat gun the image quickly got really really bad. And then, when using the...
    See more | Go to post

    Leave a comment:

  • magnusbjork
    replied to Samsung LCD heat problem...?
    in Troubleshooting TVs and Video Sources
    Re: Samsung LCD heat problem...?

    Ok, thanks for confirming that Tom.

    I just had a look at the top of the display, under the metal cover that protects the flat film cables. I'm feeling a bit unsure about poking the flat film cable connectors too much, there's 12 of them going down to the screen and they do look very fragile. Well ok, I did gently nudge them a little bit but there's no effect. I also tried to apply a bit more pressure on the two (white) flat cables coming from the LVDS (?) cable split connection.

    I'll reattach the metal cover over the flat...
    See more | Go to post

    Leave a comment:

  • magnusbjork
    replied to Samsung LCD heat problem...?
    in Troubleshooting TVs and Video Sources
    Re: Samsung LCD heat problem...?

    I heated the power board a little bit (really gently with the heat gun) and the voltages went to;

    13,0V m (Main?) = 12,55V
    5,1V = 5,06V
    13,0V s (Second?) = 12,99V

    ...So basically no big difference in voltages.

    And this _might_ just be my imagination but I think that I heard a brief little high-pitched "squeip"-sound a few seconds after switching off the heat gun. (Capacitor leak?) And now the picture quality is bad...

    Good ideas?

    Thanks,
    Mag...
    See more | Go to post

    Leave a comment:

  • magnusbjork
    replied to Samsung LCD heat problem...?
    in Troubleshooting TVs and Video Sources
    Re: Samsung LCD heat problem...?

    Thanks for confirming that randtek. So I guess the 5,1V is out of the list of suspects then. That leaves us with the "almost 13V" line.

    For measuring I'm using my trusty old Fluke 75. It's been around but I think it's still fairly accurate.

    ...So, after ~45 minutes, there's still the same voltages. (Picture quality has gone down a bit.) I think I just might use my heatgun _very gently_ on the power board to see what happens to the picture and the voltages. I'll keep you posted.

    Thanks,...
    See more | Go to post

    Leave a comment:

  • magnusbjork
    replied to Samsung LCD heat problem...?
    in Troubleshooting TVs and Video Sources
    Re: Samsung LCD heat problem...?

    Hi Tom & co,

    I had a look for the voltages and I think that we might be on to something here...

    The voltage(s) measured at startup (=cold TV) on the 24-pin connector "CN801" are as follows;

    13,0V m (Main?) = 12,56V
    5,1V = 5,06V
    13,0V s (Second?) = 13,02V

    This is with the TV still relatively "cold". It's heating up as I write this and I'll post more values in ~30 minutes and 1 hour from now. That will be interesting to see when the colors go...
    See more | Go to post

    Leave a comment:

  • magnusbjork
    replied to Samsung LCD heat problem...?
    in Troubleshooting TVs and Video Sources
    Re: Samsung LCD heat problem...?

    Nope, I did not try to add heat. (Yet.)

    I'm slightly worried that the "cooling spray" didn't have any effect at all on the PCB components. So just in case, if it's screen-related, what could it be? (I did not try to "cool the rear of the screen", only the PCB:s)

    Thanks again!

    Cheers,
    Magnus
    See more | Go to post

    Leave a comment:

  • magnusbjork
    replied to Samsung LCD heat problem...?
    in Troubleshooting TVs and Video Sources
    Re: Samsung LCD heat problem...?

    Hi Tom,

    thanks a lot for your reply!

    Ah, of course. I'll see if I find a moment to check the power supply outputs tomorrow. I'll keep you (all) posted.

    Fingers crossed it's not a screen problem. But if you say that even that is fixable I guess there's hope...

    Cheers,
    Magnus
    See more | Go to post

    Leave a comment:

  • magnusbjork
    started a topic Samsung LCD heat problem...?
    in Troubleshooting TVs and Video Sources

    Samsung LCD heat problem...?

    Hi all electronics Gurus!

    Here's a first-time post from France, (just across the border to Geneva, Switzerland.)

    I have a strange problem with a Samsung LCD that I bought second hand. (Yes, out of warranty.)

    --- ID ---
    Samsung 40" LCD television
    Model no: LE40A536T1FXXC
    Serial no: AT4F3SLQA12103N
    Version: CN01
    Mainboard: BN94-02459A (Well, um, if I found the right sticker?)

    --- Some symptoms ---

    When switching it on cold there's no problems at all with it, all works perfectly fine...
    See more | Go to post
No activity results to display
Show More
Working...
X