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Re: LG 49UB850V not switching on / standby LED off / LD701 blinks 5x
Need to give a correction, the burned choke is input for 1.2V voltage regulation, not output.
If I short the choke the buzzing noise is gone, but still this fancy PWM signal on output side...
No short measureable, also the 12V input is stable. Maybe its burned during some of the tests before. Because the buzzing noise i've recognized first during the test in #18Attached FilesLast edited by Seb932; 09-19-2023, 08:22 AM.Comment
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Re: LG 49UB850V not switching on / standby LED off / LD701 blinks 5x
jumper it and let the game start... other wise buy replacement MBComment
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Re: LG 49UB850V not switching on / standby LED off / LD701 blinks 5x
by the way do you have 5V USB?Comment
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Re: LG 49UB850V not switching on / standby LED off / LD701 blinks 5x
log capture use TTL adapter 3.3V level and any terminal to capture the log
for waking up.. plug USB mouse and another USB stick you put on it root any MPG4 movie , start moving & clicking on mouse left and right while you plug the tv in wall socketComment
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Re: LG 49UB850V not switching on / standby LED off / LD701 blinks 5x
When you hear an unusual buzz, you need to use a stethoscope or rubber hose or such to try and pinpoint where it's coming from.Comment
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Re: LG 49UB850V not switching on / standby LED off / LD701 blinks 5x
Might have a bad solder joint somewhere, those will also cause a buzz.Comment
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Re: LG 49UB850V not switching on / standby LED off / LD701 blinks 5x
Thought as much, that was just for those that might see this and be wondering how to check it, sometimes it's hard to tell exactly where a noise is coming from.Last edited by nomoresonys; 09-19-2023, 09:40 AM.Comment
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Re: LG 49UB850V not switching on / standby LED off / LD701 blinks 5x
What is the final outcome of this thread? I have the same TV with the same problem (at least it looks that way).
So I would like to know the root-cause of this and see if it could help me with mine…..Comment
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Short Update - TV is working again. BGA Reflow of IC100 does the trick.
Long Story:- PWS,Edgelit,T-Con,Panel was working (checked before)
- Previous missing voltages, all voltages are there, but my measurment method wasn't correct. I've partly measured directly on the IC output, which is before the LC part => I've measured the direct output frequency without smothing...🤦
- All voltages on MB are correct, no further ideas beside BGA reflow
- start with IC100
- stipped down plastic parts from MB
- removed the metal cover
- Heatgun from below ~350°C
- Heatgun on top of IC100 max 550°C
- started with preheating to 200°C both sides
- followed with a short period of maximum temerature on top of IC100
- slowly cool down
- put everything together
- Power on => Everything is working 👍
Thanks for your help!
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I was correct about needing a reflow, I am also correct by telling you it will last a lot longer if you can get a fan blowing on the IC.Comment
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I have wanting to do this project for quite sometime now and I finally found a switching power supply that will work on this desoldering gun station ZD-915 that the original switching power supply took a shit and just was not worth trying to fix it because this switching power is not quite big enough to handle the heater element and the vacuum pump
One note when I tested the switching power supply and the voltage control board I noticed that this desoldering gun heat up much faster than the original switching power supply which I was really surprised by to the point that I might buy... -
I have been working on this concept for quite some time now with limited success but recently I found a switching power supply that is setup for the voltage that this soldering station needs to operate at however it also needs part of the secondary circuit from the original switching power because you need several voltage rails
I once tried to get a ZD-915 desoldering station to work on a 18 volt battery power supply but unfortunately things did not go well but I did find a work around but I might try this idea again but going at a little differently more about this another time... -
My Samsung UE75TU7020k lights up fine when one of the ribbon cables are disconnected from the main board, lights stay on but not getting half a picture, I do the same with the other ribbon and put the other one in and lights stay on but not getting half a picture. The standby light flashes 2 times then reboots then it then tries to come back on again and just keeps looping until I take either one of the ribbon tables out (doesn’t matter which one I take out it stays lit when either one is out). I’ve tested the backlights but all working with none shorting out, I’ve replaced the main board... -
I am a noob with some elementary knowledge trying to fix this TV that I have no history on. Any help or guidance will be much appreciated.
When I first examined it was completely dead. saw that the fuse was blown and the ICM801CS blown. I searched and found that the FSFR1800HSL might be the replacement and got one from ebay and replaced it. But when I pulled the ICM801CS I could see the last 3 letters on the blown up part was XSL. So may be I replaced it with the incorrect part. I fixed the fuse and turned it on and it now gives me a standby light blinking twice five times, then clicks... -
Hello,
I am currently troubleshooting an LG 60UH8500 TV (2016 TV). Any help or suggestions would be appreciated.
Overall Issue: When TV is turned on, backlights all come on for about 10 seconds, then all go out. There is sound and there is a picture on the display (obviously hard to see without backlights, but it is there).
What I Have Done So Far: 1) Removed the back TV cover to expose the boards (Power Supply, Tcon, and Main), 2) blew out any dust and cleaned all connections, 3) Noticed that the LED backlights are fed from two separate connectors...
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