LCD Projector problems? (1 Viewer)

[Carl Hood]

Hi,

My Sony projector starts out fine from cold, but after about an hour or so one small portion of the display (around middle top)seems to take on a slight green cast. "Dark" movies with greys are most affected. For example smoke from a chimney in a movie scene will start out blue/grey then as it passes through the affected area of the display the smoke turns sickly green then back to blue/grey. Similarily, off-white walls are tinted with green in the affected area. The rest of the display remains perfect (or at least consistent). It is very noticable on B/W movies. Very annoying.

Might I have a problem with the LCD panels themselves, associated electronics, or maybe excessive heat? It isn't something I have been able to correct via normal user adjustments.Before I return my projector to a service centre, I would really like to get some idea of what might be happening.

Thanks. Carl.

 

[Neil Joseph]

Does your LCD projector have more than one temp setting? Perhaps it is a combintion of this and the type of screen creating a hot spot in the viewing area?

 

[Carl Hood]

The projector has two temperature settings - High (optimised for PAL white temperature) and Low (optimised for NTSC white temperature). I use high by default. I tried the low setting which reduced the impact of the hot spot, but it was still there. Overall, the low setting has too much red push which I find objectionable. I guess if I adjusted gain/bias to reduce the red, I would be left with the original problem. Although I can enter the service mode, I don't like to muck around with these settings too much because I'm not really sure what I'm doing. I operate the projector in a totally dark room so my screen is a simple affair - just a matt-white fabric stretched across a frame. No "gain" as far as I know. I don't need a high-gain screen. But your point is well taken. I should point out the hot spot only occurs with shades. A pure white or highly saturated colours display (from Avia disk) are perfect apart from some obvious dust accumulation somewhere on the optics internally.

My projector is 3 years old (VPLX600) and the lamp has 720 hours.

Appreciate the response! - Carl.