TV Forums

Free Games TV Forums

  Main Index FORUM
HOME
Search Posts SEARCH
POSTS
Who's Online WHO'S
ONLINE
Log in LOG
IN
Rules & FAQ RULES
F.A.Q.

Crumbtrail TV Forums: TV Equipment: TV Repair Forum:
JVC 32x576 TV With Weird Green Pixelated Screen Pattern

 

 


jmkvavle
New User

Dec 6, 2008, 5:24 PM

Post #1 of 13 (3816 views)
Shortcut
JVC 32x576 TV With Weird Green Pixelated Screen Pattern Can't Post

I've got a broken HD Tv. It's a JVC 32X576. It's a few years old and one day when turning it on the screen just showed a strange pixelated pattern,
which is mostly green, some red squares, and some white and black as well. The volume still works just fine, but the picture is messed up.
The menus still work as well. I can access any of the menus, and change the settings. I can even do do the split, and freeze screen options, but
then I get two weird green screens. I've checked all of the inputs, but the video doesn't work in any of them, while the audio does.

I performed a Self Check by pressing the sleep timer button and then the Video status and display buttons at the same time.
I pressed "2" to enter the Self Check Mode.

The results of the self test were all ok, except for the Sync M, Sync S and Sync HD. Sometimes the RGB also has an error but that error goes
away after I run the test again.

I bought the service manual for this TV, and found that those tests correspond to the Main Sync Signal, the Sub Sync Signal, and the Component
Sync Signals respectively. The service manual indicates that this error happens from the Analog Signal PWB (IC201).

So, I opened up the chassis and everything looks pristine. I checked all the connections, took out the Analog Signal PWG, looked for any
blown capacitors, but everything looked good. I put everything back together, and tested it again with the same results.

I thought maybe if it's the Analog Signal PWB that has the problem, I could just input a digital signal into the HDMI port and that maybe it
would work. I don't have any equipment with an HDMI output. The manual for this TV says that the HDMI port on this TV isn't compatible with
the DVI of a computer. I assumed that maybe they just meant it isn't compatible with the DVI-A port of a computer. I have a DVI-I port on my
video card, so I tried plugging a DVI-D to HDMI cable from my computer to the HDMI port of the TV. Something definitely happens. The TV screen
goes black and then turns back on again with the same weird screen pattern, this time with some scanning bands that look like they're probably
coming from my computer. There are no such bands on the other inputs even when I have a video signal going in.

My next step would be to purchase a new Analog Signal PWB, but I'm afraid that since the digital input also didn't work, maybe there's another problem.

Have any ideas?

Thanks.



zip
User

Dec 6, 2008, 7:52 PM

Post #2 of 13 (3809 views)
Shortcut
Re: [jmkvavle] JVC 32x576 TV With Weird Green Pixelated Screen Pattern [In reply to] Can't Post

can you post a photo of the problem?


zip
User

Dec 6, 2008, 7:56 PM

Post #3 of 13 (3807 views)
Shortcut
Re: [jmkvavle] JVC 32x576 TV With Weird Green Pixelated Screen Pattern [In reply to] Can't Post

how do the menu screen display's look ok or same pixalation on them?


jmkvavle
New User

Dec 6, 2008, 8:40 PM

Post #4 of 13 (3806 views)
Shortcut
Re: [zip] JVC 32x576 TV With Weird Green Pixelated Screen Pattern [In reply to] Can't Post

Thanks for your willingness to take a look into this problem. I put some pictures in a directory that you can access here: http://www.et.byu.edu/~jmk34/JVC32x576/

As you'll be able to see, the menus render without any problem.

I've also put a pdf of the service manual in the directory with the pictures.

thanks,

jmkvavle


zip
User

Dec 6, 2008, 10:00 PM

Post #5 of 13 (3799 views)
Shortcut
Re: [jmkvavle] JVC 32x576 TV With Weird Green Pixelated Screen Pattern [In reply to] Can't Post

looks like you have a bad digital signal PWB, or I see they (JVC) have a new firmware download for this set which
may address this problem.


jmkvavle
New User

Dec 6, 2008, 11:03 PM

Post #6 of 13 (3796 views)
Shortcut
Re: [zip] JVC 32x576 TV With Weird Green Pixelated Screen Pattern [In reply to] Can't Post

Why do you think it's the digital signal pwb vs. the analog? I really don't have any experience with these things. I thought that maybe since the menus looked ok, that was part of the digital signal board...

thanks,

jmkvavle


(This post was edited by jmkvavle on Dec 6, 2008, 11:04 PM)


zip
User

Dec 6, 2008, 11:46 PM

Post #7 of 13 (3790 views)
Shortcut
Re: [jmkvavle] JVC 32x576 TV With Weird Green Pixelated Screen Pattern [In reply to] Can't Post

yes the osd is generated on the digital board but late in the path as it exits to the lcd panel itself, and most of the signal processing is handled earlier on the digital board, and if you checked all the inputs componet,composit,s-video and the analog board is just basiclly just a switching board. It sure looks to be on the digital board to me maybe someone else will chime in on this one.


zip
User

Dec 7, 2008, 12:13 AM

Post #8 of 13 (3789 views)
Shortcut
Re: [zip] JVC 32x576 TV With Weird Green Pixelated Screen Pattern [In reply to] Can't Post

You also don't want to run a jvc set with the rear cover removed, see the note in the service manual.


jmkvavle
New User

Dec 8, 2008, 6:56 PM

Post #9 of 13 (3771 views)
Shortcut
Re: [zip] JVC 32x576 TV With Weird Green Pixelated Screen Pattern [In reply to] Can't Post

I don't think that I turned the TV on when I had the cover removed. If I did have it removed would that be catastrophic?


zip
User

Dec 9, 2008, 4:26 AM

Post #10 of 13 (3760 views)
Shortcut
Re: [jmkvavle] JVC 32x576 TV With Weird Green Pixelated Screen Pattern [In reply to] Can't Post

It's a copyguard issue you will lose all HD inputs.


jmkvavle
New User

Dec 17, 2008, 1:59 AM

Post #11 of 13 (3737 views)
Shortcut
Re: [zip] JVC 32x576 TV With Weird Green Pixelated Screen Pattern [In reply to] Can't Post

Thanks, so much zip. I got a replacement board and that fixed the problem! You are the best!


iwillbackit
User

Dec 17, 2008, 7:07 AM

Post #12 of 13 (3733 views)
Shortcut
Re: [zip] JVC 32x576 TV With Weird Green Pixelated Screen Pattern [In reply to] Can't Post

I've also put a pdf of the service manual in the directory with the pictures.

thanks.


buy cheap DVD

The Simpsons Seasons 1-19 DVD Boxset $200


digital-dump
New User

Feb 17, 2009, 7:03 AM

Post #13 of 13 (3566 views)
Shortcut
Re: [iwillbackit] JVC 32x576 TV With Weird Green Pixelated Screen Pattern [In reply to] Can't Post

I have fixed this problem with JVC digital boards before. I'll fix anyones digital board from a JVC if it has almost these exact symptoms! But you would probably have to send it to me unless your in the phoenix,AZ area. - lcdmonitorrepair@hotmail.com

 
 
 


Search for (options) - Page loaded in: 0.13 s on (CGI/1.1)
0