Re: LG 50PN4500 - fluctuating Vcc/18V supply on Y-sustain board causing fault
Good fix, thanks for the update.
Good fix, thanks for the update.
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Re: LG 50PN4500 - fluctuating Vcc/18V supply on Y-sustain board causing fault
I'm chasing somewhat of the same issue. Started with a shorted cap at c204 between Vcc and gnd of Ic201 (200d6). replaced with a 50uf (original was 100) to check and everything worked for about 10min.
replaced Ic201 based on OP's xperiences as everything else seemed to test fine, as well as replacing C204 with the proper value.
Blew out the 2.0 ohm resistor and the driver FET Q202.
replaced those and IC201 again(as a precaution), and got fluctuating voltages on the high voltage pin of IC201 .
IC201 was showing high frequency bursts on the gate of the FET, and as I was continuing to probe it blew out the 2.0 ohm resistor and the FET again.
I've checked all around that area and components seem fine.
Any advice?Comment
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Re: LG 50PN4500 - fluctuating Vcc/18V supply on Y-sustain board causing fault
If i remember correctly I blew the same FET and resister once because I had the ic-201 removed from the circuit when I powered up the board. IF I remember correctly there is a small transformer located next to the IC-201, FET and resistor. Make sure incoming/outgoing voltage is good on that. make sure all connections and solder joints are good in the area also. A cold solder joint will cause some weird symptoms and have you chasing ghost.
Also remember there is a floating ground and a chassis ground on that board.Comment
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Re: LG 50PN4500 - fluctuating Vcc/18V supply on Y-sustain board causing fault
Thanks, I've given the board a good look over, but I'm sure my tired old eyes may have missed something.
I'll report back when I've had another go at it.Comment
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Re: LG 50PN4500 - fluctuating Vcc/18V supply on Y-sustain board causing fault
Just gave up and bought a used y-sus for $45. back up and running!Comment
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Re: LG 50PN4500 - fluctuating Vcc/18V supply on Y-sustain board causing fault
Hey as long as it is working.Comment
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Re: LG 50PN4500 - fluctuating Vcc/18V supply on Y-sustain board causing fault
I am looking for C417 and C418 value. Does the rated value is 500v ?
Thank you.Comment
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Re: LG 50PN4500 - fluctuating Vcc/18V supply on Y-sustain board causing fault
I believe they are 0.022uFComment
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Re: LG 50PN4500 - fluctuating Vcc/18V supply on Y-sustain board causing fault
Thank you very much for the answers of Beau28713 & R_J
You can see a picture of these caps here:
http://www.coppelltvrepair.com/p/154...-image-problem
On the left and right they are C416/415 & C401/402 that seems similar to the couple C417/418.
The dielectric is light grey then the value could be low but also different because the height is not the same.
It is not for me but a colleague so I Don't have the board.Comment
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Re: LG 50PN4500 - fluctuating Vcc/18V supply on Y-sustain board causing fault
I do believe R_J is correct in saying they are .022uF and around 500v. The safest way to proceed would to just buy the repair kit. That way you will have the correct caps and plus you will have some spare parts in case you need them.Comment
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Hello everyone. 😀
As per thread title, this unit has a serious SMPSU fault. It blows F1001, which is a 10A M205 in the phase from the mains input.
Very first thing I tried, was simply replacing the fuse, but the replacement ceramic fuse blew immediately.
Looking at the schematic for this PSU, I then removed what I thought was the next likely candidate: D1001 - the HV main bridge rectifier.
This isolated the fault(no longer blows the main fuse), but does not point me to the actual fault.
There are no devices that have exploded or otherwise show signs... -
Good day all,
I got a 2007 MacBook from a friend. The fan was not working so it was overheating.
Once the fan was swapped, I installed an OS and it worked fine.
The board had quite a few corroded spots so I removed it, touched those spots with a soldering iron, washed the board in PCB cleaning fluid (I've done that many times), rinsed it with distilled water, dried it etc.
Unfortunately it doesn't work anymore. It does turn on, fan spins, power LED turns on. But no picture.
If I see that right, I have missed VCORE on L7100 (page 59).... -
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Upon bringing it home and plugging it up, it showed a standby light.
I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.
The screen seems to blackout and stay black, but with a flashlight I can see the display.
With my Playstation 4 connected via HDMI, and running a game I can hear sound.
Assuming... -
Hi There,
This TV was auto switching off after few seconds with some vertical lines on the screen, so got a new TCON board and replaced it.
After replacing the TCON board it was working fine and i set it up with everything, used for few hours, then had the bright idea to update the software on it. During the update process, TV switched off and now no audio or video. No relay switch sound.
More Details
TV Model - LG OLED77G1PUA
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