CurtPalme.com Home Theater Forum

karlandreasa · Posted: Mon Jan 11, 2016 1:35 am Post subject: Nec XG75, Lines "giving up"

This is a wierd one.
After approx. 2hours the picture has slowly moved left about a Cm and this happens: https://drive.google.com/file/d/0BxV1FUMq9NdOU0pTVnI5NFQxQ2c/view?usp=docslist_api

Everything goes back to normal when you switch input and then back (or, last time, only by pressing any remote-button so that the overlay starts).

I have a Moome-card and tun a pc with 1080i. Also a ps3 with 1080i (but i'm not shure i've seen it on the ps3)[/url]

**Curt Palme** · Posted: Mon Jan 11, 2016 3:57 am Post subject:

What I would do is measure exactly where the test grid is, and see if that moves the cm as well. If not, then I would suspect a source/Moome issue and not a projector problem. If the crosshatch moves as well, then the problem is within the projector.

karlandreasa · Posted: Mon Jan 11, 2016 11:11 am Post subject:

I will check! I forgot to say that the coloured lines at the bottom appears suddenly after those 2h and is slowly sinking/bending down

gjaky · Joined: 05 Jun 2010 Posts: 2790 Location: Budapest, Hungary

The coloured lines at the bottom are caused by raster roll over. It seems you don't use any vertical blanking, with that you can hide those lines. Also you can try to set "position" so your picture remain within the raster.

**Curt Palme** · Posted: Mon Jan 11, 2016 5:46 pm Post subject:

He's right, or you can use raster shift to move the image up/down, and then use the tilt on the mount to compensate to get the image away from that problem. It can still be the signal, but you may have a problem with the H/V shift board in the set. I've got spares if you need one.

karlandreasa · Posted: Wed Mar 02, 2016 1:31 pm Post subject:

Hello again! sorry for the late, late answer and thanks for your help:)
-The crosshatch moves slowly to the left aswell and the lines start sinking (but only if i leave it on for a while since everytime i get the overlay up it resets (both position and sinking lines at the bottom).
-I will try to move the picture inside the raster but it looks like the picture uses every line from the top to bottom. what do i do then? do i have to sacrifice something?
-I have a working spare-projector (bad/missing tubes), if i would swap the H/V shift board, do i have to redo the set-up process to make everything fit? anything i should know?
-I talked to a CRT-friend in sweden that talked about interference from for-example bad/worn-out caps in the Powersupply that messed up something and that the projector went through some sort of re-sync-process every time i push for-example "store". Is that something i should try swapping aswell?

gjaky · Joined: 05 Jun 2010 Posts: 2790 Location: Budapest, Hungary

The projector needs some time to stabilize the adjustment, although, but a few cm seems a bit much.
-Myebe you should reconnect the deflection yoke cables.
-If you want to play with boards I'd suggest the OSC or Wave boards for start.