Joined
·
772 Posts
I started to have flickering after 30 hours on my new Sony VPL-HW55ES projector. At first I thought I had a bad unit. I'm still not certain about the cause, but I suspect it is bulb flicker, which I am reading is one of the most common and annoying problems that can be had with projectors.
So I thought I'd start a thread to explore this topic a little more, since it can be the bane of many that choose front projection for their entertainment needs.
I'll post a little of the research I have read that seems most relevant, but I'm hoping those of you that know more can please post what you know.
It would also be nice if people have flicker to post here the make/model, and number of hours on the bulb. Maybe we as consumers could note some trends that might be informative.
CAUSES...
Bulb flicker appears to be most commonly caused by something called "arc wander" and "arc flare". Can also be power quality issues or projector ballast/power supply issues, but these are less common.
This site has a great illustration of the problem: http://zeiss-campus.magnet.fsu.edu/tutorials/arclampinstability/indexflash.html
Arc wander can happen for various reasons, but it is when the arc start/end points wander on the electrodes, causing the arc's brightness to fluctuate.
AVSForum member "coldmachine" describes it well: "The point at which the arc strikes begins to move slightly on the electrode, and makes a track that the arc "wanders" along. When this occurs, flickering frequently results. A period on max power may solve it, but if the arc track is well established, it cant be reversed. Its a fundamental problem with any arc discharge lamp. The good news is that its a lamp issue, not a PJ issue."
A description of some of the causes I found (http://www.film-tech.com/ubb/f1/t003983.html):
The arc looks like a candle in the wind.
This can happen under some of these circumstances:
1. The cathodes and anodes are badly eroded due to age or defect.
2. Deformed anodes and cathodes due to poor power supply filtering.
3. Deformed anodes and cathodes due to excessive in-rush current.
4. Deformed anodes and cathodes due to long igniter "lay-on's."
5. Weak or mis-adjusted magnets if the bulb requires the use of them.
6. Operating a bulb with magnets when it does not want them.
7. Stray magnetic fields getting too close to the bulb.
8. Bulb being operated outside the recommended electrical parameters.
9. Bulb being operated outside the recommended mechanical parameters.
I'm also assuming manufacturing defects or quality control can make a bulb prone to this as well.
I also would suspect some bulb designs are more prone to the problem than others, as well as bulbs with lower quality control, third party knockoffs, etc.
One thread suggested that the Sony bulb (LMP-H202 - my bulb) is more prone to the problem that some. It's used in their HW30/40/50/55/95.
SOLUTIONS...
The most common solutions I've read:
- Switch to another lamp power mode (i.e. from high to low or from low to high) for a few hours, then back to your preferred bulb mode
- Usually it is to switch from low to high, as low or eco mode is more prone to the problem
- Change picture modes and then switch back
- Get a new bulb
- Run in high power mode for the first few tens or hundred hours on a new bulb to establish solid strike points for the arc
- Then switching to low power mode the arc will be less prone to develop wandering
- Place a magnet over the lamp area, if the wandering conditions are suitable that may stabilize the arc. Do at your own risk though of causing other problems with PJ
Most of these only seem to mitigate the problem or help stop it for a while, but if a bulb is prone to it, it may be very difficult to stop
Some say that going to high lamp at the first sign can help curtail it, but if it has been going on for a long time it is likely the bulb is too damaged to get it to go away with that bulb.
- Get a laser projector!
Who knows, maybe laser light sources will come down in price, and they will be less prone to flicker problems! If they do flicker, it won't be due to arc wander, that's for sure...
I would also REALLY like people to chime in if they found it to be a power supply issue or it was fixed by moving your plug, using different power conditioner, etc.
So please, if you have more info on the causes, solutions, or just want to complain about your bulb flicker problem - post it here!
So I thought I'd start a thread to explore this topic a little more, since it can be the bane of many that choose front projection for their entertainment needs.
I'll post a little of the research I have read that seems most relevant, but I'm hoping those of you that know more can please post what you know.
It would also be nice if people have flicker to post here the make/model, and number of hours on the bulb. Maybe we as consumers could note some trends that might be informative.
CAUSES...
Bulb flicker appears to be most commonly caused by something called "arc wander" and "arc flare". Can also be power quality issues or projector ballast/power supply issues, but these are less common.
This site has a great illustration of the problem: http://zeiss-campus.magnet.fsu.edu/tutorials/arclampinstability/indexflash.html
Arc wander can happen for various reasons, but it is when the arc start/end points wander on the electrodes, causing the arc's brightness to fluctuate.
AVSForum member "coldmachine" describes it well: "The point at which the arc strikes begins to move slightly on the electrode, and makes a track that the arc "wanders" along. When this occurs, flickering frequently results. A period on max power may solve it, but if the arc track is well established, it cant be reversed. Its a fundamental problem with any arc discharge lamp. The good news is that its a lamp issue, not a PJ issue."
A description of some of the causes I found (http://www.film-tech.com/ubb/f1/t003983.html):
The arc looks like a candle in the wind.
This can happen under some of these circumstances:
1. The cathodes and anodes are badly eroded due to age or defect.
2. Deformed anodes and cathodes due to poor power supply filtering.
3. Deformed anodes and cathodes due to excessive in-rush current.
4. Deformed anodes and cathodes due to long igniter "lay-on's."
5. Weak or mis-adjusted magnets if the bulb requires the use of them.
6. Operating a bulb with magnets when it does not want them.
7. Stray magnetic fields getting too close to the bulb.
8. Bulb being operated outside the recommended electrical parameters.
9. Bulb being operated outside the recommended mechanical parameters.
I'm also assuming manufacturing defects or quality control can make a bulb prone to this as well.
I also would suspect some bulb designs are more prone to the problem than others, as well as bulbs with lower quality control, third party knockoffs, etc.
One thread suggested that the Sony bulb (LMP-H202 - my bulb) is more prone to the problem that some. It's used in their HW30/40/50/55/95.
SOLUTIONS...
The most common solutions I've read:
- Switch to another lamp power mode (i.e. from high to low or from low to high) for a few hours, then back to your preferred bulb mode
- Usually it is to switch from low to high, as low or eco mode is more prone to the problem
- Change picture modes and then switch back
- Get a new bulb
- Run in high power mode for the first few tens or hundred hours on a new bulb to establish solid strike points for the arc
- Then switching to low power mode the arc will be less prone to develop wandering
- Place a magnet over the lamp area, if the wandering conditions are suitable that may stabilize the arc. Do at your own risk though of causing other problems with PJ
Most of these only seem to mitigate the problem or help stop it for a while, but if a bulb is prone to it, it may be very difficult to stop
Some say that going to high lamp at the first sign can help curtail it, but if it has been going on for a long time it is likely the bulb is too damaged to get it to go away with that bulb.
- Get a laser projector!
Who knows, maybe laser light sources will come down in price, and they will be less prone to flicker problems! If they do flicker, it won't be due to arc wander, that's for sure...
I would also REALLY like people to chime in if they found it to be a power supply issue or it was fixed by moving your plug, using different power conditioner, etc.
So please, if you have more info on the causes, solutions, or just want to complain about your bulb flicker problem - post it here!
