Repair of LG 42LW5700 TA, LED TV, Part 4

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  • Опубликовано: 29 окт 2024

Комментарии • 26

  • @paulomorales
    @paulomorales 5 лет назад

    Thanks a lot, i repaired not one but two dead TVs of mine with your method ! Thanks for sharing your knowledge !

  • @surewill8190
    @surewill8190 3 года назад

    i also repaired this model tv , with reheating the chip , thanks for you video and time take to do , it would have a lot more time than what the tv is worth but the information gained was very good , if this fails again i have found iphone 12 stensil for reballing of this chip , i also not like how lg have mounted the heatsink , with plastic spring loaded clips and metal springs on the board , replacing these and placing heatsink compound , surly help this chip as well

  • @ricardoaeromodelista
    @ricardoaeromodelista 7 лет назад +2

    Reflow in lead free solder does not work, all your work returns. Do the correct, reballing the chip! Reflow to confirm that the defect is even on the BGA ok, then replace the beads with leaded solder. Good job!

  • @TheRochlan
    @TheRochlan 6 лет назад

    Thank you for a series of very interesting videos. I've got a very similiar model (LG 42LW5500) that shows the same problems as yours did (power board seems to be ok). I will try reflowing of the main graphics chip using my resoldering hot air station. But since the chip itself seem to be genererally sensitive to temperature, in order to avoid it failing again I was considering to permanently mount one or two 4x4cm active fans outside the chassis (same as you did in the video when you did your temperature measuring). Since the TV offers 12V on the video board, I was wondering whether I could take the power for those fans directly from there (by soldering a 2-pin wire that leads outside of the chassis through one of those holes, where I would connect the two fans. Do you see any problem with such an approach?

  • @alpe3182
    @alpe3182 8 лет назад +1

    Thank you very much Richard, I could repair my tv, bug use a hair dryer, jejeje . Thanks again

    • @richardrudek01
      @richardrudek01  8 лет назад +1

      Your welcome.
      Hair dryer... Hmm. I can understand that. No point letting it go to waste. I've not needed to use mine for ~ 3½ decades... :)

    • @norsyahidasaidi4443
      @norsyahidasaidi4443 8 лет назад

      Thanks to you Richard save me RM 650. and to you to Alejandro with idea of using hair dryer, it works!!.
      but somehow, my first try just works for 2 minutes. then my second try works but small vertical line appeared if look closely. from far it not bugging me.
      hope it will stay works for a year at least before change to a new one. thanks again for this vid.

    • @richardrudek01
      @richardrudek01  8 лет назад

      Your welcome.
      Another hair dryer. Wow.
      Clearly these failures are not with the BGA balls, but internally with the chip. I still have not had any response from Broadcom to my questions about the package construction (for example Flip-Chip) nor JTAG details.
      That aside, I should point out that whilst a Hair Dryer is fundamentally the same as a Hot Air rework station, the differences are very important. For example, a Hair Dryer is *NOT* designed to operate a 200+ ℃. That is, reflowing solder.
      Indeed most should have cut-off switches that prevent it exceeding more than about 60℃. Even if you bypassed that, I'd be surprised if it would *safely* survive 150℃ (Celcius).
      Be sensible, people.

  • @clavallegiannoni
    @clavallegiannoni 6 лет назад

    Good afternoon, you will have the video mainbord of that model that you are repairing, how much would it cost in dollars, my TV is turned on and off after being turned on for 5 minutes, at the beginning everything is fine, but then it fails. greetings from Lima, Peru

  • @mohamedRajab-yy6px
    @mohamedRajab-yy6px 7 лет назад

    Dear RichardI have the same problem in the same model. can I use the heat gun to heat BGA as you did ? what the estimated time?must I put flux on the BGA?

    • @richardrudek01
      @richardrudek01  7 лет назад

      It looks like the problem is due to stress fractures inside the BGA package. So heating the BGA chip up to more than it usually operates, say 120 Degrees Celsius, seems to be enough to get it working again - at least for a short time.
      So if you have a temperature controlled oven, it's probably better to use just the oven itself. No need for a heat gun.
      Though a heat gun does have the advantage of being able to use it on the main board while it is still in TV. Choose your poison...
      But as has been said in the comments here a few times now, *IF* this heat treatment works, it is only temporary - the more thermal cycles the BGA package is subjected to afterwards, the quicker the connections fail again.
      If your interested, you can look at this document from Texas Instruments:
      www.ti.com/lit/ug/spru811a/spru811a.pdf
      On page 8, Figure 1, you can basically see another, much smaller package inside the outer BGA package. This smaller package is similarly connected via much smaller conducting "bumps", and the theory is that it is those bumps that have become unreliable. As the BGA heats and cools everything expands and contracts, leading to fractures after about 1000 thermal cycles due to metal fatigue.
      The "fix" is to then heat the package up to more than usual, so everything expands just a little bit more, mashing the connecting materials together enough to (sometimes) make it work again.

    • @mohamedRajab-yy6px
      @mohamedRajab-yy6px 7 лет назад

      I completely lost my main board for 43LW5700 can you help me to get new main board

  • @filbaytee1118
    @filbaytee1118 8 лет назад

    Rich, thanks for the vid. I got pretty much zero volts on that drive measurement on my 47" LG powered on and the same slow pulsing red light. can you provide a link to a gas heater as yours but on Amazon? web is full of folks baking boards and having luck, but at much higher temps (200 C I think?) but your reasons seem safer. Also is your TV still running after 6 months???

    • @richardrudek01
      @richardrudek01  8 лет назад

      (I hate the You tube comment editor, just lost the whole reply...)
      Yes, I wanted to try and diagnose the faulty chip, not just "reflow" the whole board. Besides, there is a downside to "reflowing" the whole board:
      EEVblog #782 - The Dangers Of Reflow Soldering: ruclips.net/video/U7soJAFbKwY/видео.html
      In terms of a hot air tool, *IF* I were to go out and specifically buy one for this job, I would *NOT* be buying a gas-based one - the exhaust has quite a lot of water vapour in it. Instead I'd be buying what I can afford in terms of a proper Hot Air rework station - this is in terms of copying what I did.
      But if your planning to properly reflow the chip, even a 600+ Watt hot air rework station is unlikely to be successful with this huge BGA chip in terms of:
      - Getting the chip off.
      - Not lifting a pad from the main board.
      - Getting a good replacement chip or re-balling the chip yourself.
      - Correctly soldering the replacement back on.
      Take a look at the link I gave roket iskandar about the type of equipment, or rather, the procedures you need to replicate in order to get the damn chip off.
      And yes, the TV was still working when I moved it off the bench. Powered it up a couple weeks ago, still fine.

  • @hans7403
    @hans7403 7 лет назад

    Richard a lot of thanks! I have an 42lw5700 but an thunderbolt caused damage in HDMI ports only. all functions works correctly, can I repair the pcb replacing something? wihout complete PCB ? because in my country is very expensive in cost benefit with another new tv; thanks so much best regards...

    • @richardrudek01
      @richardrudek01  7 лет назад

      I don't know:
      - Can you remove and install Surface Mount components (successfully)?
      - Can you obtain the parts?
      - Are you extremely motivated?
      Even if the answer to all three questions was yes, the result may still be no.
      Lightning has a habit of crawling over everything. So it may have taken out not only the HDMI port processor and\or whatever it is connected to, but the Voltage regulators and\or anything those are connected to. It could also have Carbonised between the layers inside the PCB in various spots. So the severity of the incident should be a major part of the assessment process.

    • @hans7403
      @hans7403 7 лет назад

      Richard Rudek Thank you so much for quick answer.. Yes I have motivation, and I have knowledge about electronic pcb with surface components, I know the lighting damaged the HDMI and VGA ports and an blu ray conected I think the lighting opened. a way across the PCB starting with the HDMI connected in an DVR connected with security cams ...so I have to start in HDMI ports? or in the power supply? can yo help me with an diagram of this pcb's? thanks! again best regards...

    • @richardrudek01
      @richardrudek01  7 лет назад +1

      I don't remember exactly where I found and downloaded the service manual from. But it is out there. My copy is 115 pages long. I'm not sure exactly what its filename *was*. Might have been "lg_42lw5700-ta_chassis_lb12c_mfl67007003_1103-rev00.pdf"
      I can't give you my copy, as in Australia, that would be copyright infringement. If you find a site but it is now down, then a copy might be cached on archive.org. Good luck.
      But yes, I'd start with the Voltages, keeping an eye out for burning components.
      The HDMI Port Processor is apparently a Silicon Image Sii9287B. IC701. Follow the PCB traces from the HDMI ports.
      Unfortunately, it looks like the Sii9287B further connects to the Main SoC processor. The thing I "abused" in this video. A very large BGA package... I doubt heating that would make any difference though, being a lightning strike, and all.
      Good luck.

    • @hans7403
      @hans7403 7 лет назад

      Richard Rudek Richard! really a thanks so much... I'm know where I have to start... I will try it ... people like you are pure gold! thanks! the information is the most important thanks for share...

  • @oscarflorez6073
    @oscarflorez6073 3 года назад

    Excelente me ayudo con una placa igualita y me cirvio

  • @elvisgarrido6512
    @elvisgarrido6512 8 лет назад

    Necesito reparar un lg 42L W5700, tienes un contacto para llamarte o escribirte?

  • @soya0
    @soya0 8 лет назад

    Bad service...reballing bga !!!!

    • @richardrudek01
      @richardrudek01  7 лет назад

      Yes I agree. Reballing *this* kind of BGA package is a waste of time, and money.
      The fact that I, and a couple of others have (temporarily) "fixed" the problem by heating up the BGA package, in some cases by less than 100 Degrees Celsius, suggests a failure inside the BGA package.
      If your interested, then search for flip-chip-BGA internals, which is what I suspect is the case here *(unconfirmed)*.
      For example, from Texas Instruments: Flip Chip Ball Grid Array Package Reference Guide:
      www.ti.com/lit/ug/spru811a/spru811a.pdf

    • @TVHOGAR66
      @TVHOGAR66 4 года назад

      @@richardrudek01 this is not a "Flip -Chip" mecanichal falilure due to strees in the solder joints occurs, if you replace solder balls whit tin lead ones, then permanent fix