Joined: 06 Dec 2008
|Posted: Sat Dec 06, 2008 1:02 am Post subject: JCV LT32x576 Weird Green Pixelated Screen
|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?