Annoying white dots on your projector screen? We know all about that.
Projection technology has indeed advanced. However, it is not quite flawless.
After using a projector for a while you may notice white dots. They develop on your displayed image.
What causes these white dots? Can my projector develop white dots too?
If you have these questions, this article is for you.
It explains the phenomena of white dots on projector screens. We also give a detailed guide to fixing this problem.
- What Causes White Dots on a Projector Screen?
What Causes White Dots on a Projector Screen?
Have you noticed white dots on your projector screen? Chances are it is due to one of two reasons:
- Failing pixels in DLP projectors
- Dust accumulating on projector bulbs
Failing Pixels on DLP Projectors
DLP Projectors make use of DMD chips (DLP chips). DMD chips are digital micro-mirror devices.
The chips are made up of thousands of tiny mirrors. The mirrors reflect and deflect light to make up an image.
The amount of mirrors a projector has, translates to the amount of pixels it has.
DLP projectors are very common. They produce good quality images due to a high amount of pixels.
However, no system is perfect. DLP projectors are usually plagued with spots on the projection screen.
Spots appear when the DMD chip begins to fail. The pixels spoil and stop functioning properly.
The spots on the projector screen can be either white or black. White spots appear when pixels are stuck in the on position.
It is unavoidable. The only question is ‘when?’
Why do DLP chips go bad?
DLP projectors have high sensitivity to heat. White dots on projection screens are caused by pixels damaged by heat.
Dust may build up and clog the air vents. This will prevent the projector from cooling properly.
The environment also plays a role. DLP projectors in hot areas will develop spots faster than those in cooler areas.
When the tiny micro-mirrors begin to fail, there’s no stopping them. They will fail progressively.
More white dots will appear until they take up the whole screen. The process is irreversible.
There is only one fix: You have to change the projector’s DMD chips.
How Do You Fix a White Dot on a Projector Screen?
The DMD chip is found in the optical engine of the projector. You have to replace a failing chip.
Follow these steps:
- Turn off the projector and unplug it from the main switch.
- Let it cool.
- Remove the projector case. Unscrew any screws holding it in place.
- I’ll suggest you take a picture of the main board. This will help you recall the placement of things.
- Unplug any cables from the board. The cables are for the lens, lights and cooling fans.
- There are screws holding down the optical set. Unscrew them.
- Bring out the optical set and take it apart.
- Behind the heat sink, you will find the DMD chip.
- Take out the DMD chip.
- Replace the old chip with a new one.
NB: Use thermal paste between the new chip and the heat sink. It reduces the gaps between them.
When the gaps are reduced, heat dissipates quickly. This helps to keep the DMD chip cool.
Dust Accumulation on Projector Lamp
Often dust gets into the projector. It enters through the vents.
The vents are there to help the fans let in cool air. However, dust particles get in along with the air.
The fan may even help push the particles into every corner of the projector.
When dust gets on the lamp, it blocks out light in tiny areas. This gives a dot on the projector screen.
How To Fix Dust Accumulation on Projector Lamp
This problem has an easy fix. Also, it does not need replacements.
- A can of compressed air
- A screwdriver
Just follow these steps:
- If you recently used the projector, let it cool for 30 minutes.
- Loosen the screws and take off the lamp cover.
- Loosen the screws that secure the lamp and pull it out.
- Hold the lamp by its handle, don’t touch the glass. It breaks easily and can cause injury.
- Use a can of compressed air to carefully blow away dirt.
- Put the lamp back and screw it in.
- Screw on the cover.
1. What are the advantages of DLP projectors?
DLP projectors are widely in use. This is because they have many benefits.
A DLP projector is not as high-maintenance as an LCD projector. It has a sealed-chip design.
This means that dust cannot get on the chip. If the mirrors don’t get dusty, the image will not have dust spots.
DLP projectors do not show signs of color decay. Also, their images are never misaligned.
2. Can you fix a dead pixel on a projector?
Quite simply, no. You cannot fix a dead pixel on your projector.
Once pixels start dying, it means the chip is failing. The best solution is to change the DMD chip.
3. Why does my projector have black dots?
Failing DMD chips can cause black dots. The dots show that the image on the screen is incomplete.
DMD chips contain tiny mirrors. When these mirrors are damaged, spots appear on the screen.
What do black dots mean? They may mean that a pixel has gotten stuck in an off position.
A pixel usually goes between on and off position. This enables it to reflect or deflect light.
When this happens, you cannot reverse or fix it. You have to change the DMD chip.
If the black dots have a shadowy appearance, the projector’s light pipe may be faulty.
Projectors are constantly evolving. Newer models are brighter, sharper and more colorful.
They may be used for teaching, official presentations, or entertainment.
Projection technology ensures that our projectors work well. DLP technology has its advantages.
If you notice your DLP projector developing spots, you know what to do. Cheers!
Related post: What Is The Rainbow Effect In DLP Projectors?