(originally posted in power supply forum, reposted here)
Got a Sony KDL-32NL140 that turns on to a black screen w/ backlights. I've pulled the back cover and confirmed that they are on. No sound to be heard.
Attached are the top and bottom pictures of the TCON from ShopJimmy (not enough light right now to take decent photos of mine). Readings are as follows:
F1 fuse:
00.2 ohm while unplugged
OL diode mode
Using chassis ground as neg, both ends measure 11.97v. Shouldn't this be 12?
On the bottom on the TCON are measure points. They are as follows:
GND
INSDA_1 3.32
INSCL_1 3.32
FWP_1 3.33
VCC_1 3.33
There are two tabs connecting to the LCD.
Removing the left one shows a screen of gray on the left, white on the right. At first, it almost looks like denim jeans. After a minute,
both sides become smooth with the gray side almost on par with the white side.
Removing the right one shows a 2 inch white vertical bar on the left side, followed by gray until the middle,
then another 2 inch white vertical bar, ending with gray til the end of the screen. No "denim" effect is shown.
Ordering a new TCON is around 20 bucks. I'd like to rule out a bad panel first.
Questions:
What else can I test to rule on the TCON?
What can I do to test the panel, especially in checking for good tab bonding?
(Originally Posted by budm)
Look for VGL, VGH, AVDD, VGMA with and without cables between the LCD and the T-CON connected.
With cables connected:
VGL -6.32
VGH 26.80
AVDD 15.73
VGMA 15.29
Without:
VGL -6.34
VGH 26.80
AVDD 15.75
VGMA 15.28
Pretty much the same both ways.
Got a Sony KDL-32NL140 that turns on to a black screen w/ backlights. I've pulled the back cover and confirmed that they are on. No sound to be heard.
Attached are the top and bottom pictures of the TCON from ShopJimmy (not enough light right now to take decent photos of mine). Readings are as follows:
F1 fuse:
00.2 ohm while unplugged
OL diode mode
Using chassis ground as neg, both ends measure 11.97v. Shouldn't this be 12?
On the bottom on the TCON are measure points. They are as follows:
GND
INSDA_1 3.32
INSCL_1 3.32
FWP_1 3.33
VCC_1 3.33
There are two tabs connecting to the LCD.
Removing the left one shows a screen of gray on the left, white on the right. At first, it almost looks like denim jeans. After a minute,
both sides become smooth with the gray side almost on par with the white side.
Removing the right one shows a 2 inch white vertical bar on the left side, followed by gray until the middle,
then another 2 inch white vertical bar, ending with gray til the end of the screen. No "denim" effect is shown.
Ordering a new TCON is around 20 bucks. I'd like to rule out a bad panel first.
Questions:
What else can I test to rule on the TCON?
What can I do to test the panel, especially in checking for good tab bonding?
(Originally Posted by budm)
Look for VGL, VGH, AVDD, VGMA with and without cables between the LCD and the T-CON connected.
With cables connected:
VGL -6.32
VGH 26.80
AVDD 15.73
VGMA 15.29
Without:
VGL -6.34
VGH 26.80
AVDD 15.75
VGMA 15.28
Pretty much the same both ways.
Attached Files
I don't have a problem with getting another main board but I am interested in if there is a way to test panels that aren't cracked. Is there a method?
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