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Discussion Starter · #1 ·
I have a problem with my Sony VPH-1272QM. Part of the image jitters or fluctuates horizontally (left-right). This "waving motion" is most noticeable when there is text on the picture (e.g. subtitles, end credits or on-screen menus). I use subtitles very often because english is not my native language.


Here are some notes about the problem:


- The waving occurs only with PAL signal. NTSC image is rock steady. I live in PAL country (fV = 50Hz) and our line voltage is 230V, 50Hz.

- I use progressive DVD player (Nintaus PDVD-N769) and VGA cable

- The waving is worse with progressive signal (VGA, fH=31.2kHz, fV=50Hz) than with interlaced signal (S-Video).

- The waving gets worse with anamorphic squeeze. Without anamorphic squeeze the waving is hardly noticeable, but it's still there.

- Only part of the image is waving, not the whole image.

- The place and intensity of the waving changes over time.

- I have tried blowing the white molex plug with compressed air, but it didn't help.

- I don't think it's the ground loop problem. I tried connecting the DVD player and the projector in the same socket and left all the other equipment unconnected. Didn't help. Could it still be a ground related problem?

- Sometimes I notice a little sparkle when I connect the VGA cable to the DVD player and the other end of the cable is connected to the projector.


Any ideas what might be wrong??



MrMMo
 

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Did you try changing the horizontal sync options on the Sony Setup screen? I was losing sync on my VPH1272 when dark NTSC images appeared, but after playing with the sync options it solved the problem.
 

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Discussion Starter · #3 ·
I am sorry, but I am not sure what sync option are you talking about. Do you mean the polarity of the H/C-SYNC, which is found on the PAGE 4; Input Info? But this is just information about the input signal, you can't change it. Or are there some other sync options that I'm not aware of?


My PAGE 4 looks like this:


Input Info

fH: 31.2kHz

fV: 49.9Hz

H/C-SYNC: NEG

V-SYNC: NEG

SYNC ON G: ---

INPUT SIGNAL: RGB

REGI BLOCK: No.4



MrMMo
 

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Yes - sync options on setup page 4. I found on some sources they were a don't care, i.e., 480i, 480p, 720p, and 768p from scaler. However, when I went to 1080i, the sync polarity became critical.
 

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Discussion Starter · #5 ·
Okay, but still - How can you change this sync option??? It is not a parameter you can change, but just an information about the input signal. Are you sure that you changed the polarity of the H/C-SYNC from your projector and not from the scaler? I don't know anything about scalers. I am using progressive scan DVD player with progressive PAL signal (576p).


Could you (or someone else) please explain me how to change the polarity of the H/C-SYNC? Or do you have any other good guesses what is causing the jitter?
 

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You can try hooking it up to a PC, set for different resolutions and refresh rates, and see if the jitter's still there.


The only differences between PAL prog and NTSC progressive are res (480p vs 576p) and scan rates. A CRT really doesn't care about the res being fed, so it's down to the scan rate. You have to make sure the problem's with the CRT, not the Nintaus' output, that's why I suggest you try it with a PC.
 
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