Re: LG 42LG3000 LCD TV Fault Finding.
Forgive my n00bness tom66, but how might I go about doing that with this board? I'm guessing you mean this one?
https://www.dropbox.com/sh/1wope3wgi...2017.13.15.jpg
From what I understand, what you're saying is, the mainboard is checked using 5v - perhaps for Standby, if everything checks out and the power button is pressed, the mainboard tells the PSU to fire up the 12v to power the backlight. If the mainboard is failing to tell the PSU (or the PSU is failing to provide 12v) to fire up, it wouldn't be there... hence why the screen is going off - although the backlight does fire up, but goes out within a blink of an eye.
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Re: LG 42LG3000 LCD TV Fault Finding.
Check the PS ON signal from main board is turning on first, if it does not send that signal 12V will not come up.Leave a comment:
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Re: LG 42LG3000 LCD TV Fault Finding.
Just used a multimeter on the PSU outputs of 5v and 12v.
5v reports 5.13v.
12v reports nothing at all.
Seems the PSU is at fault then? Is it worth fault finding and replacing components or better to just replace the board?Leave a comment:
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Re: LG 42LG3000 LCD TV Fault Finding.
First thing I would check is the resistance on each coil of the backlight transformers. See if they are the same. Use a mutimeter on Ohms, Next check would be the output voltages on the power supply- most of the time the values are written on the board next to the connectors.Leave a comment:
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LG 42LG3000 LCD TV Fault Finding.
Hi Badcaps, great forum, incredibly helpful members and hopefully kind enough to lend a hand with this TV I'm having problems with.
Searched the forum and found similar issues with no definitive answer, so had to create a new thread.
I am new and only repaired a couple of sets in the past, so please go easy and have some patience with me. Thanks.
Took my 42LG3000 apart in the lounge and trying to suss out the faulty board.
Here is a video of the symptoms...
http://www.youtube.com/watch?v=LCWH8EON5j8
It can't really be seen in the video, but after the backlight flashes, the LED light on the right is a steady faint blue, so power still remains. I'm not sure of what the LED colours are meant to be when operational as I've only just acquired the set 'as is'.
At first I suspected the Invertor boards. Disconnected them and tried the TV. LED remains faint blue.
Next, disconnected TCon board. Same thing. LED remains faint blue.
Only boards left are the PSU and the mainboard. The mainboard controls the LED so from here I'm a little stumped. All Capacitors appear in good shape, although I do not know for certain.
Anyone willing to lend some experience on how to test the boards or advise what I'm doing wrong or even to just take the mickey because I've done it all completely wrong?
As recommended, here are the images of the inside of the set and the boards. Not shot the TConn Board yet, still covered over with the plate.
Photo's on Dropbox -
https://www.dropbox.com/sh/1wope3wgily61mh/JIPb_JyU8b
Tried embedding them, but didn't work.
More available on request.
Opinions on another forum point towards the PSU, but I'm not sure as it powers on and stays on. So thought I'd 'Ask the Experts'.
Will post all findings and results in here to help any other members in the future needing assistance with this Telebox.
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I have this LG 42LG3000 Tv which operates on all inputs without any issues whatsoever. However when you try to turn the Tv off the screen goes blank as it would normally however it then turns itself back on again!
So far I have replaced the main board without any resolution to the problem.
When the inverters master and slave VIT71053.54 VIT71053.55 are disconnected from the power supply then the TV will turn off as it should (obviously without any ccfl output).
I have read through a few posts for this model without anyone having this issue as far as I can tell.
I... -
- Prior owner tried a replacement main board. No difference.
- Samsung 2x red blinking standby LED = panel fault
- Jumpered FB_TRDY_1 (pin 1 CN1300 left. main tcon->left side buffer boards) and FB_TRDY_3 (pin 95 CN1301 right. main tcon->right side buffer boards) This allows testing individual T-Con (on main board) connection to panel on this Samsung. Found fault on left side (viewing from rear of TV)
- Each side has 2 buffer boards, disconnected left side flex between 2 buffer boards. Fault is on the left most board.
- Tape masking eventually isolated to CN1300 pin 15 (CKV4_GOA) Display
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I have been having a fun time at work with two pieces of equipment that had shorted components or shorted component cables to machine frame
I would check what my multi meter was telling me about how many ohms I getting with the multi meter was telling versus the ESR was telling me about weather or not it really was a short to machine ground or not
One note at first we thought that it might be a bad I/O card or a malfunction PLC including me as well but I thought I would try and see if removing the I/O cables would make a difference or not and this time it did make a difference... -
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The monitor has two main PCBs. The first one is located under a metal shielding and contains the main power supply, backlight supply, HDMI inputs, and connectors for the power button, menu controls, and power led. The second board is connected to the panel via permanently attached flex cables;... -
Hello,
I have a strange fault with a Lenovo ThinkPad E14 G2 (Board No. NM-D011 Rev. 1.0).
The first Problem, which I fixed already, was a dead TPS65944AD (USB Type-C) controller. After I fixed this fault, all functions working fine and the notebook run very well with the charger and battery.
On the next day, I tied to start the notebook with the battery, but nothing happened. I started with the charger and on windows, I saw, that the battery was empty. And this was nearly impossible, because the battery was charged. I disconnected the battery and found out, that the board...
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