Re: Samsung LE46N87BD TCon problem?
Bump......
What does VGH and/or VGHC stand for and where does the power go to, gate IC or driver IC?
mick1992
Member
Last Activity: 01-12-2017, 04:07 AM
Joined: 12-12-2016
Location: Bremen
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Re: Samsung LE46N87BD TCon problem?
here is a close up of the pad I think could be causing the problem. Sorry about the low res, took the photo with my smartphone with 6x zoom then zoomed in on that on the pc......Leave a comment:
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Re: Samsung LE46N87BD TCon problem?
so VGH voltage is only for the gate ICs (attatched to TABs on the sides of panel) and not for the the ICs attached to the TABs along the top of panel?
would this cause vertical lines?
Or only picture distortion problems??
Sorry for so many questions, I am new to this.Leave a comment:
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Re: Samsung LE46N87BD TCon problem?
Here I have 2 photos, the first is from the flexible PCB on the top left side of the panel. The points on this is where I should check for voltages as you have described, correct?
The second photo is from the driver board on the top of the TV, where the ribbon coming from the panel connects. If you look closely you can see one of the pads the ribbon connects to looks burnt out, tracing this back along the board it connects to the VGHC test point.
So if I don't get a reading on the flexible PCB on the side of the...Leave a comment:
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Re: Samsung LE46N87BD TCon problem?
OK this is more or less a bump up as I was dropping down the list and I have a feeling many people don't really look past the first page.
Really need some help here
What job does the VGHC signal do?
If the VGHC signal doesn't make it to the driver IC would this show symptoms of a failed driver IC/ failed TAB?? (e.g. vertical black stripe approx 2 inches wide)
I have been searching for information on this with no luck, would really appreciate if a tech could explain what the VGHC signal...Leave a comment:
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Re: Samsung LE46N87BD TCon problem?
This one pin definitely looks shot! It runs to the VGHC test pin from what I can tell.
Can someone please explain to me what VGHC is and could an open circuit here be causing my vertical stripes?
(The stripes are on the far left and the damaged pin connects to the furthermost TAB on the left)Leave a comment:
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Re: Samsung LE46N87BD TCon problem?
This one pin definitely looks shot! It runs to the VGHC test pin from what I can tell.
Can someone please explain to me what VGHC is and could an open circuit here be causing my vertical stripes?
(The stripes are on the far left and the damaged pin connects to the furthermost TAB on the left)...Leave a comment:
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Re: Samsung LE46N87BD TCon problem?
OK guys another update...
Measured the VGMA voltages and entered them into Tom's Spreadsheet, and got a fail on gamma monotonicity and gamma symmetry.
Before I order the replacement gamma IC I need some advice!
With the left driver board disconnected from the Tcon I can still see the 2 big vertical stripes on the left side of the screen (see pics).
Does this mean the panel itself is damaged, or the IC to TAB bonding has failed or is there a chance it could still be the TAB to driver board bonding?...Leave a comment:
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Re: Samsung LE46N87BD TCon problem?
Another update:
Looks like the original TCon has been reworked by the guy I bought the tv from, it has an R5101 gamma IC....
The new TCon has an AS51-F.
So I'm going to go ahead and order a new IC and fit it to the new TCon board. I will test the VGMA voltages before ordering to be 100% sure but after doing some research I have a strong feeling this is what is causing the screen to be washed out and lacking colour.
If this solves the problem then all that's left is 2 dodgey tab bonds...Leave a comment:
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Re: Samsung LE46N87BD TCon problem?
OK, Will test again tomorrow, need to get the multimeter again.Leave a comment:
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Re: Samsung LE46N87BD TCon problem?
UPDATE!
New TCon and I now have solid picture!!!!!!!!
Now to the next problem.....
Picture is washed out and ghosting (see pics) settings don't change the picture at all (contrast, brightness ect)
What could cause this? Maybe I need to update the firmware?? (TCon is the correct part no. ect. but it came from a different model TV)
Also I have 2 solid white vertical stripes on the left side of screen, I'm guessing the tab bonds are causing this, but applying pressure to the tab bonds or the small...Leave a comment:
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Re: Samsung LE46N87BD TCon problem?
....Leave a comment:
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Re: Samsung LE46N87BD TCon problem?
The horizontal lines you see in the photos of the screen are from interference from the camera and not showing on the screen itself. You can use the picture of the green screen for reference, this was solid colour with no horizontal lines...Leave a comment:
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Re: Samsung LE46N87BD TCon problem?
OK update
Voltages on TCon
12v IN - 13.5v
GAVCC1 - 3.3v
COM2 - 10.5v
VCC - 3.3v
COMF2 - 10.5v
AVDD - 15.5v
AVDD1 - 15.5v
VCOM2 - 10.5v
VCOMF2 - 10.5v
AGMODEN - 3.0v
VGHC - 28.2v
EXWP - 3.2v
VED5 - 2.4v *** is this supposed to be 5v???
VED3 - 3.2v
Source board voltages
Right side
AVDD - 15.5v
V3D3 - 3.3v
XVCOM - 10.5v
COMF2 - 10.5v
VGL - 5.9v
VGHC - 28.2v
COM - 10.5v...Leave a comment:
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Re: Samsung LE46N87BD TCon problem?
Ok so when I check these voltages I should have the negative grounded on the chassis and use the positive probe on the board, correct?
Panel doesn't have driver boards on the side, only 2 boards along the top. It does have some things that look like ribbons on the sides of the panel but aren't connected to anything. When testing the 2 boards on the top what voltages should I be seeing?
I will grab the multimeter from work tomorrow and check these, then post an update.Leave a comment:
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Re: Samsung LE46N87BD TCon problem?
OK, capacitor's arrived today, TCon arrives in a couple of days, when these are installed if the picture is still messed up I will try some thermal pads on the panel ribbons.
Will keep you updated, if there is anything else you guys come up with please let me know.Leave a comment:
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Re: Samsung LE46N87BD TCon problem?
OK guys so here's the thing, I'm a mechanic by trade, and I have some experience repairing circuit boards with normal sized components, but this is my first time repairing a TV. It only cost me 30 bucks, so if I can't fix it its no big deal but I want to give it a shot.
I have access to some soldering equipment, I don't have a heat gun type solderer but I do have a normal "hairdryer" type heat gun with an attachment nozzle that has an outlet about 8mm wide, its a good one from Mercedes with a digital display and I can...Leave a comment:
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Re: Samsung LE46N87BD TCon problem?
Is this repairable?Leave a comment:
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Re: Samsung LE46N87BD TCon problem?
OK quick update, so took another look at the TV, when the TV is cold I can see the menu and vertical/horizontal lines, lasts about 2 minutes then fades away to a solid white screen. Here are some pictures....Leave a comment:
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Samsung LE46N87BD TCon problem?
Hi Guys, new here, Im an Australian currently living in Germany.
Need some help with my Samsung LE46N87BD 46" LCD (its a European model, and the TCon is a AUO T460HWO2). I bought for 30 bucks, the guy I bought it off said it wasn't turning on so thinking it would be an easy fix (cap's) I went ahead and bought it.
Got home, plugged it in and it turned on but the screen was completely covered in different coloured vertical lines. (pretty sure the guy knew about samsungs dodgey caps and swindled me knowing it was something else)
Caps look good,...
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