Symptoms of vibration damage to projectors?

[pete]

We have two rooms where the projectors are inexplicably dim, even after changing bulbs, checking filters and even the lens assembly to check if the colour filters are yellowing.

 

Projectors of a similar age are fine.

 

However, the ceilings they are attached to noticeably vibrates. The projected image moves up and down when students in the classroom above move around. The classrooms are 50/50 brick/wooden framed construction and the upper floors do have a noticeable bounce to them.

 

Is it feasible that the vibration could make the projector dimmer? I was thinking of it shaking electrical connections loose, but can't think how it would damage the lens assembly in such a way to cause dimming.

[PEO]

pete. most projectors have a setting to increase brightness. have you looked to see if there is such a setting?

 

what model/make are they

[greenfieldsupport]

I think the vibration could damage the bulb when its hot, but it'll be on or off, shouldn't really lose brightness.

 

is it not that those rooms are brighter?? i.e. have more background light to the other rooms??

[pete]

@Mr Happy

Yeah, we know about the brightness setting. They're Sanyo PLC-SE20As. We have about 15 of these.

 

@greenfieldsupport

The rooms are brighter, and that's what we initially suspected, but with all the lights off and curtains drawn at 4.30pm in November, it's still dim to the point you can't see the setup menu clearly.

 

If the bulb is new and known good, the brightness is set to high, and the lamp starts ok, would the lamp dim due to power supply issues? My understanding is that if the power supply can get the lamp started, it should work at the required brightness (but I could be wrong).

[Ste_Harve]

I've had a lot of problems with sanyo projectors if the filters haven't been cleaned regularly. What i do is take the projector to bits and clean all the internal mirros and it makes a massive difference, If you do this though make sure you put things back in the right order or you can end up with funky displays!!!!

[Andrew_C]

I think the vibration could damage the bulb when its hot, but it'll be on or off, shouldn't really lose brightness.

Not very likely really. These lamps are short-arcs and as such don't have filaments. The vibration could conceivably moved a mirror/prism out of alignment, but I don't think it's hugely likely.