CurtPalme.com Home Theater Forum

incova · Joined: 27 Nov 2006 Posts: 789 Location: london

Hi all, I have noticed the picture on my Ampro moving up and down very fast , I took the blanking off as I thought this may be causing some problems however it is still the same. Is this Hum in which case I can get hold of a GLI or is it something else? I cannot see it if I look on the tubes the movement is tiny but it shows on the image.

tse · Joined: 03 May 2006 Posts: 1014 Location: Sweatbucket, Fl.

Try bumping the vertical phase up or down a notch.

scott

incova · Joined: 27 Nov 2006 Posts: 789 Location: london

I will give that a go Scott, thanks, its 1.44 in the morning here so maybe in a few hours! Smile

incova · Joined: 27 Nov 2006 Posts: 789 Location: london

Tried that Scott but no luck picture is still shaky, I removed the LK5 Jumper a long time ago on your advice when I first got the pj that stabalised it a lot. I am also running it at 1920 1080p on the timings you gave me on powerstrip to prevent image cuttoff and wrap around. I tried phase in all directions but no luck, also tried size and made everything smaller horizontally and vertically still stayed the same. Could it be hum or is there anything else I can try?

lexx21 · Joined: 10 Oct 2008 Posts: 119

You say that you are using powerstrip, so I am guessing that you are using your htpc to feed the projector. Is there anything else that you can connect to it to eliminate a problem with the htpc?

incova · Joined: 27 Nov 2006 Posts: 789 Location: london

no, not at the moment, maybe over the weekend, its a good idea just in case, the picture on my crt monitor is fine though, maybe I can check the cable as well, thanks.

incova · Joined: 27 Nov 2006 Posts: 789 Location: london

Ok

I changed the cable and tried two other cables no difference. I then shut of the convergence and still no difference the picture has slight movement up and down even when convergence is off. Making the raster smeller makes no difference either as I thought I had it to close to the edges. I should be getting a test pattern generator soon so hopefully i can feed another source in and see if its the HTPC.

dvh99 · Joined: 25 Dec 2009 Posts: 2158 Location: nederland

try reducing vert sync width and maybe add some front and back porches vertically.
vbp = 20
vsync= 20 (more or less)
vfp = 20

stefuel · Posted: Mon Jul 19, 2010 8:05 pm Post subject:

Does it look almost like it's blinking every 30 -45 seconds or so?
If so........Naaaaa, I never seen it before Wink

incova · Joined: 27 Nov 2006 Posts: 789 Location: london

ummm no, no blinking Chip! the image is moving rapidly up and down but within a very small space about a cm on screen I cannot see it on the tubes. At the edges of the image it is wavy, its hard to explain, all three tubes stay in convergence but at the top and bottom edges the image is not steady. Even if I put registration off it is the same so I assume its not the convergence board. I was hunting to see if anyone had similar problems but no luck so far.

tse · Joined: 03 May 2006 Posts: 1014 Location: Sweatbucket, Fl.

If you can input a video source with 50Hz refresh (or maybe 75Hz) try it and see if the same thing is happening.

Scott

incova · Joined: 27 Nov 2006 Posts: 789 Location: london

I could just lower the refresh powerstrip on the HTPC and try that I suppose? would that be a way to test it?

tse · Joined: 03 May 2006 Posts: 1014 Location: Sweatbucket, Fl.

The idea here is to have the video refresh the same frequency as the AC power frequency. I think if you change the refresh to 50Hz and let everything else change in proportion it should be ok.

Scott

incova · Joined: 27 Nov 2006 Posts: 789 Location: london

Thanks Scott, I will give it a go tommorow.

incova · Joined: 27 Nov 2006 Posts: 789 Location: london

I changed the refresh to 50Hz buttttttttt no luck, same problem. at 75HZ it was still the same, not sure what to think now.