Sharp XG-E3000U lamp dimming
 

I've been using this projector for about 6 months with no problems
until last night. It was working fine for about 90 min, then the lamp
suddenly dimmed to about half brightness and I could hear a buzzing
noise similar to the sound it makes when the lamp is first starting.
I immediately shut it down for about 5-10 min. After powering it on
again it worked for about 55 min before doing the same thing.

The lamp was used when I got it, so I don't know how many hours are on
it. Does this sound like the lamp may be failing?

I've seen two of these projectors with bad power supplies and only one
with a good power supply (this one). Are there any known causes for
the high failure rate? Is there anything I can do to prevent it?
Both of the bad power supplies had a burnt out inductor and shorted
power MOSFETs in the lamp supply. It uses the same power supply as
the XG-E1200U and XG-E3500U.

I have the projector apart right now to clean the filters and check
for obvious problems.
Andy Cuffe

Sharp XG-E3000U lamp dimming
 

On Thu, 23 Mar 2006 10:31:43 -0800, Andy Cuffe
wrote:

I've been using this projector for about 6 months with no problems
until last night. It was working fine for about 90 min, then the lamp
suddenly dimmed to about half brightness and I could hear a buzzing
noise similar to the sound it makes when the lamp is first starting.
I immediately shut it down for about 5-10 min. After powering it on
again it worked for about 55 min before doing the same thing.



After putting it back together the lamp didn't even try to start. I
checked the lamp start circuit and found a shorted thyristor. I'm
guessing the lamp was dimming because the start circuit was activating
while the lamp was running.

The bad part is a Toshiba SF8JZ47. I subbed it with an NTE 5558 and
it seems to be working fine again.

Andy Cuffe