Geometry question, please help. (1 Viewer)

[Kenneth+S]

Hi,

I visit here often but don't post much, if at all. I do have a question though. Within the last couple of weeks I noticed that the horizontal lines on my tv dip down on the left side, facing the television. I seems to only effect the top portion of the screen. It is real noticable when watching movies in a 2.35 aspect ratio. When looking at the tv the black bar along the top of the screen will be straight on the right side of the bar, but then just towards the left side of the bar it dips down so that the top black bar looks uneven.

I am very picking about geometry issues and never noticed this before, It seems like it just started. My question is, can this be fixed?

My tv is a crt rear projection ( Mitsubishi model#WS-55313 ). It is a 03/04 model. 16x9

I do know about the service menus and actually know how to access the ones for this model. I can get to some of the functions that adjust geometry, but they seem to only stretch or squeeze the picture or adjust the vertical lines. None seem to effect the horizontal ones. (Yes, I did write down the original settings so that I didn't totally screw up my tv ). Also, before this happened I never entered the service menus, so I know this didn't happen because of me.

Please give me some advice on how to correct this, if it can be corrected.

Thanks,
Ken

 

[Cees Alons]

Kenneth,


Something like that may be caused by a magnetized screen. Do you have an unshielded speaker close to that corner? In that case: try moving it and see if you notice something happening with those bend lines.

It could also be a semi-permanent magnetization of the screen, which will often go away when it is "degaussed". That used to be a procedure you had to do manually (a specific button, or a choice inside the (maintainance) menu, but on modern CRT screens it's most often included in the start-up procedure.

To achieve that: did you already switch off the TV totally? Not just stand-by, but indeed OFF? In case of doubt, you could even remove the power connection for a short moment.
Switching it on again will probably degauss the screen. If you're not sure about that, perhaps the manual will say something about it (if it's still in your possession).


Cees

 

[Kenneth+S]

Cees,

Thanks for your reply. I do have a degaussing coil and can try that. I don't see anything in the menu about automatic degaussing.

I will try the other suggestions as well, thanks again and wish me luck.

Ken

 

[Cees Alons]

Of course we wish you luck!

Even if it doesn't say so in the manual: try a cold start first before applying the external degaussing coil. That is: after you made sure it isn't an external magnetic field (speaker)!

Again: good luck, Kenneth!


Cees