Projector Repair

**Jay_Clone** · 12-18-2012, 11:24 AM

Does anyone know a place around DM that can repair a home theater projector? I thought it was just the lamp but after replacing that I am still having the same issue.

**DJSteve** · 12-18-2012, 12:47 PM

Can't help you with a local repairman, but I have done some minor stuff myself on an older NEC DLP projector. What brand/model projector are you working with and what are the symptoms? Will the bulb light at all, or do any of the indicator lights/fans/etc come on?

I'm guessing if it's anything serious you will need to look up manufacturer-authorized repair facilities and ship it somewhere.

**Jay_Clone** · 12-18-2012, 01:06 PM

It is an Optoma HD20. The picture flickers between normal color and a green tint after it works just fine for about 15-20 mins. I'm guessing it is the color wheel but I really have no idea. I called Optoma and they want $110 just to look at it. Then it could cost a lot more to fix. The thing is only about $850 now to buy a brand new one.

**DJSteve** · 12-18-2012, 01:25 PM

Since the problem manifests itself after the projector has been on for a while (heat), I would guess the problem is with the color wheel motor as opposed to the color wheel itself. It looks like you can buy a color wheel assembly (motor+wheel+cable) on ebay for <$100, and there are several instructional videos on YouTube that show how to replace it. I'd check those out and either do it yourself or bribe a friend that's handy.

**tigershoops31** · 12-18-2012, 02:24 PM

Originally Posted by DJSteve

Since the problem manifests itself after the projector has been on for a while (heat), I would guess the problem is with the color wheel motor as opposed to the color wheel itself. It looks like you can buy a color wheel assembly (motor+wheel+cable) on ebay for <$100, and there are several instructional videos on YouTube that show how to replace it. I'd check those out and either do it yourself or bribe a friend that's handy.

I have a similar problem with an NEC projector. I was looking at buying a replacement bulb but you're saying if it works for a while it wouldn't be the bulb? Mine usually flickers blue after working fine for 10-20 minutes.

**DJSteve** · 12-18-2012, 03:13 PM

Originally Posted by tigershoops31

I have a similar problem with an NEC projector. I was looking at buying a replacement bulb but you're saying if it works for a while it wouldn't be the bulb? Mine usually flickers blue after working fine for 10-20 minutes.

If you have a picture and/or the projector works as it should part of the time, a new bulb is unlikely to fix anything. DLP works by spinning colored glass filters in front of the light source--so instead of having 3 RGB pixels in close proximity like a CRT/LCD/Plasma, each color intensity is established based on the angle of each pixel mirror as a given color passes in front of the light source. (Each red, green, blue value is established sequentially, but because the color wheel is spinning quickly you just see the net color--much like you don't see a fluorescent light turning on and off 60 times a second). When you have a color shift, that is usually because the projector is incorrectly assuming which color filter is in front of the light source--either due to a motor problem, sensor problem, or a color segment being loose/broken. The NEC projectors I have are fairly notorious for having segments break out of the color wheel in explosive fashion, however that will cause weird vibrations and the color will always be wrong. If your projector is working properly part of the time, it just about has to be something with the color wheel drive or sensing electronics.

I would start by searching google/youtube for other people that have had problems with your specific model of projector... in the case of the OP, it seems the Optoma HD20 is pretty notorious for color wheel problems.

It also might be worth opening up the projector case and trying some easy stuff (like making sure the color wheel is tight on the motor shaft, cleaning everything out with canned air, and re-seating the color wheel drive electrical connector) to see if that makes a difference before you order parts.

Note: The above advice only applies to DLP projectors--LCD projectors use a different mechanism (without a color wheel) and troubleshooting would be totally different. Most projectors intended for video/home theater use are DLP, as they generally give better black levels.

**Jay_Clone** · 12-18-2012, 03:58 PM

I opened up the projector and I smelled the color wheel and it smells like it has been overheated. I ordered one off ebay with a return policy of 60 days. Thanks DJSteve for the help. Hopefully it works out.