Re: LG 32" 32LG50FD whitish picture
Thanks for your reply tom66, after looking at U502 under a microscope I can just make out it's part number. It's an E-CMOS AS15-F, a 14 channel reference voltage buffer. According the application note this chip buffers a bunch of resistive divided references. This is good news; it might be easier to source than an AUO chip and it might just be a resistor on the string of referernce inputs which is open or shorted. A picture is attached of the typical application circuit....
mohhingman
Member
Last Activity: 02-27-2013, 01:51 AM
Joined: 05-14-2012
Location: Queensland
-
Re: LG 32" 32LG50FD whitish picture
Hello All,
The voltage readings from the good T-Con board have been measured. A picture is attached of the board's voltage generation circuitry. It's a AUO T315HW01 V0. Different voltages in bold.
General Voltages - Good, Bad
V12IN: 12.0, 12.0
V12: 12.0, 12.0
VGL: -6.0, -6.0
VGH: 27.3,27.3
AVDD: 16.5,16.5
VGHC: 25.8,25.7
[B]VCOM: 6.7,15.8[/B]
VGMA_REF: 15.8, 16.0
CONF: 6.7,6.7
VIDE:1.8,1.8
V2REF:2.5
XSFT_M:1.3,1.3
...Leave a comment:
-
Re: LG 32" 32LG50FD whitish picture FIXED
OK, great news on the 32LG50FD LCD set which had a white picture. It has been fixed with a replacement of the T-con board. I would like to thank all those who posted here giving me advice on where to start. A picture is shown with the replacement T-con board fitted and running a test source on the screen. This was a 2nd hand part from an internet vendor.
So for those running AUO screens which have gone white, it is due to a bad T-con board. I am lead to beleive the problem is in the LCD bias voltage generation circuitry....Leave a comment:
-
Re: LG 32" 32LG50FD whitish picture
Thanks for your input crtfool. I plan to keep testing this set of boards until I determine if it's panel or tcon. I did a search and stumbled across a great resource for LG LCD tvs. Albeit it's a different a model but it may be a good starting point for checking voltages.
[url]http://www.scribd.com/doc/78050578/2011LCD-37LK450-Training[/url]
I'm now inspecting the TCON board closely for voltage problems.Re: LG 32" 32LG50FD whitish picture<...<br /> Thanks...Leave a comment:
-
Re: LG 32" 32LG50FD whitish picture
Ah i see, thanks for that budm. This T-con board uses the TI 65161. By examining the feedback resistor values I imagine the correct voltages can be ascertained. Say the voltages went too high, would it damage the panel itself? One of the application notes in the 65161 datasheet has a VGH of 27.5V, VGL of -6V and a VS of 16V, which matches the readings on the T-con board. If the voltages are within spec, is there another thing to check on the T-con board or could the panel be damaged? CheersLeave a comment:
-
Re: LG 32" 32LG50FD whitish picture
Thanks a lot tom66, i'l get my hand on a new t-con board. Thanks for putting me in the right direction
I'l post results once the new board is obtained and fitted.
Leave a comment:
-
Re: LG 32" 32LG50FD whitish picture
Hi tom66, i did a voltage measurement of VGH and VGL pads on the tcon board, VGH=27V, VGL=-6.0V
cheers
Mark...Leave a comment:
-
Re: LG 32" 32LG50FD whitish picture
Thanks for your reply Tom66.
It's an AU Optronics T315HW01 screen, with a T315HW01 V0 T-Con board....Leave a comment:
-
Re: LG 32" 32LG50FD whitish picture
This is a photo of the colour problem....Leave a comment:
-
LG 32" 32LG50FD whitish picture
Hello All,
I got a 32" LG LCD which has a colour problem.
The image is mostly white, but if brightness is maxed you can make out some of the image. Parts of the image persistently stay on the screen. There are some green and pink tints in some of the images. There are no borders, double images, vertical or horizontal lines. The image just has whacked colour.
I have tried spraying the screen borders with freezy spray - no change.
I have tried using a heat gun and freezy spray on the tcon board, power supply and also mainboard -...
No activity results to display
Leave a comment: