VIZIO VX37L HDTV10A has messed up color

[triplefour]

i picked this TV up from the recycling place for 20bux because it mostly works but just has a color problem. the guy said it was most likely the TCON board. does that seem right? i guess first thing ill do is take it apart and check for loose connections and blown caps. but how do i accurately test the TCON board if its not something obvious?

[triplefour]

Re: VIZIO VX37L HDTV10A has messed up color

as you can probably guess, the pink is not supposed to be there

[Alastair E]

Re: VIZIO VX37L HDTV10A has messed up color

Probable Gamma fault--Check the Vgama voltages....

[triplefour]

Re: VIZIO VX37L HDTV10A has messed up color

vgamma..sounds cool. how do i check that?

[Alastair E]

Re: VIZIO VX37L HDTV10A has messed up color

Try a search on 'Gamma' and 'AS15'.....

[triplefour]

Re: VIZIO VX37L HDTV10A has messed up color

so its a chip on the TCON board? i havent taken the tv apart yet...just about to do that

[triplefour]

Re: VIZIO VX37L HDTV10A has messed up color

ok so i took it apart.....too many screws!!
i took pictures of all boards
the tcon board is underneath the mainboard and powerboard.
i disconnected the left cable of the tcon board and powered it up
and i got one half of the screen black and the other half still showing messed up colors.
i disconnected the right cable and reconnected the left cable and i got crazy vertical lines all over the whole screen, and i could just barely make out the menu screen faded in the background.
im not really sure how this testing of the TCON board works i only know i read other people doing it so i figured id try it too and post the pictures.
so check it out and let me know what you think is happening.
thanks again!

[Glitcher]

Re: VIZIO VX37L HDTV10A has messed up color

See where it is labeled Vgamma1..2..3 etc
Report all your measurements for each here.

Hmm, I dunno about the vertical lines, usually that indicates a bad panel when one end of the tcon is disconnected. But first lets check your gamma voltages.

[triplefour]

Re: VIZIO VX37L HDTV10A has messed up color

whew that was a lot of measurements.

ok if we look at the picture and say we have 2 rows of pins
a top row and a bottom row
the top row goes like this:
7.29
3.10
4.01
4.34
4.86
6.82
7.56
10.47
10.8
12.27
15.22
and the bottom row goes like this:
0.31
2.55
3.54
4.63
6.68
7.32
12.96
10.49
11.41
13.45
15.36

what do we know from this?

[triplefour]

Re: VIZIO VX37L HDTV10A has messed up color

please let it not be a bad panel

[Glitcher]

Re: VIZIO VX37L HDTV10A has messed up color

I can't tell from your labels how the numbers are going but you'll have to put it in the correct order

Vgamma1
Vgamma2
Vgamma3
.
.
.
Vgamma22

[SlickClick]

Re: VIZIO VX37L HDTV10A has messed up color

Vizio LCD units are well known for panel failures... If there is solid vertical lines more than likely a panel failure... However when I took these panels apart I found that the reason they say its a bad panel is because the display board are soldered to the ribbons of the panel so when there is a IC chip failure on one the render it a panel issue; I believe it can be fixed or in the least those boards swapped off using a low heat gun... otherwise is a wash...

Id like to say it the t-con causing the pink haze... I bet if you play a movie for a few hours it will get worse eventually...

[triplefour]

Re: VIZIO VX37L HDTV10A has messed up color

i had it on for 30 minutes at least maybe an hour and i didnt notice it getting worse..
ok heres the revised table of voltages:
the rightmost pins of each row are vgamma1 and 2
vgamma --- voltage
1 - 15.36
2 - 15.22
3 - 13.45
4 - 12.27
5 - 11.41
6 - 10.8
7 - 10.49
8 - 10.47
9 - 12.96
10 - 7.56
11 - 7.32
12 - 6.82
13 - 6.68
14 - 4.86
15 - 4.63
16 - 4.34
17 - 4.01
18 - 3.54
19 - 3.10
20 - 2.55
21 - 7.29
22 - 0.3

[triplefour]

Re: VIZIO VX37L HDTV10A has messed up color

how would i know what voltages they should be?

[SlickClick]

Re: VIZIO VX37L HDTV10A has messed up color

if i recall all the voltages should go down in a pattern to like 1.5 volts looks like 21 and 22 has an issue...

[Alastair E]

Re: VIZIO VX37L HDTV10A has messed up color

AS15 Gamma ref. chip--almost certainly faulty.

Be sure to get the one with the same suffix, as in 'G' 'F' or 'U' They are pretty cheap, I paid about a fiver for two not so long back....

[triplefour]

Re: VIZIO VX37L HDTV10A has messed up color

sweet so its not a bad panel just a bad chip?? can i actually replace this chip? its surface mounted yea? i never did one of those yet...

[Alastair E]

Re: VIZIO VX37L HDTV10A has messed up color

Yup, its a SM chip, but with care, can be replaced with normal iron and methods, Look on youtube, there's some vids of it being done.

Only one thing--Make sure when you're fitting the new one, be careful of the alignment, check with strong eyeglass that all four sides of pins are exactly on the pads--Makes soldering easier and less likely to short between pins....
Also--Make sure pin 1 is in the right place--Yup, Ive done it!

[triplefour]

Re: VIZIO VX37L HDTV10A has messed up color

i cant seem to see a chip on here that says AS15 on i...

[triplefour]

Re: VIZIO VX37L HDTV10A has messed up color

oh wait i see it... but theres so many tiny legs!! how can i solder that with just regular (super crappy) soldering irons?