Barco DP2K-10S – Blue Blotch Bottom Right (Prism Contamination or Blue DMD?)

[Hong Sung Hyeok]

Both Christie and Barco have a gap between the prism and the DMD water block.
Something could have leaked into that small gap, like dust, oil, or liquid that dried and remained... There are many possible scenarios.
Generally, you'll need to send the entire light engine to Barco for optical cleaning.

When you open the box for a replacement refurbished light engine, you'll notice a sour smell. I suspect it's from the chemical cleaning process.

[Dave Macaulay]

I don't know of anything before the prism or after it to possibly affect a single colour. The most likely problem is some foreign material between the DMD and prism face. I have never seen that in a Barco with what they say is a "sealed" light engine. I have seen it in Christie and NEC projectors.
I wouldn't try disassembling the prism, personally. But do what you think is best. This isn't just "a part" of the projector, it is the heart of it - and the most expensive single replacement part.
Barco has an exchange/repair process but possibly it's just for in-warranty projectors. I've replaced many, and at least Barco sends the entire assembly... unlike NEC who send just the prism with DMDs so we have to swap over the frame, cooling assembly, and wiring from the bad one.

[Mukesh Kumar]

Hi kindly check Integrator Rod. Kindly move little bit is spot is movin then you need to clean integrated Rod.

[Fandi Arbianto Dewanggi]

Hi everyone, thanks for all the response,

I ended up disassembling the light engine and accessing the red DMD optical path. After removing the DMD lens assembly, I found a small contaminant/particle that was partially obstructing the red DMD surface in exactly the area where the spot appeared on screen.
I carefully cleaned the affected area using a proper lens cleaning cloth, reassembled everything, and the spot is now completely gone.

I'm still not entirely sure how that particle managed to get in there, considering the DMD assembly should be a fairly sealed optical path. But the important part is that the image is now back to normal and the contamination has been removed.

I want to sincerely thank everyone here for the guidance, suggestions, and diagnostic input. It really helped me narrow down the source of the issue faster. I appreciate the support from this community.

[Ryan Gallagher]

I carefully cleaned the affected area using a proper lens cleaning cloth, reassembled everything, and the spot is now completely gone.

Sometimes there are rewards for bravery! TI has these instructions for cleaning DMDs. Certainly not all kit I would have handy... I'd say you got pretty lucky!
https://www.youtube.com/watch?v=pENBixO053g

[Marco Giustini]

Very interesting. That's quite some dust for a "sealed engine" - though the S10 suffered of improper filter designs at the beginning. In fact, you might want to check that your S10 has the necessary mods or it will just be a dust-sucker.

And given the amount of dust you found on Red, it might be a good idea to clean the others too - or maybe it's just pushing your luck too much ?

Thanks for sharing!

[Leo Enticknap]

Nicely done! That's braver than I would have been. That having been said, as Series 2 projectors get older and their owners can't afford outright replacement/upgrade, I suspect that we'll see more field servicing techniques being developed that OEMs never intended to happen.

Certainly not all kit I would have handy...

image.png

You mean you don't have an ionizer and a serious, lab grade microscope in your booth?!

Apart from those two items, the other kit isn't too difficult or expensive to get hold of. Distilled water, IPA (well, at least one of the two liquids known by those initials - I'd be a bit worried if the other was to be found in a typical projection booth!), and acetone are to be found in many booths anyways.

[Steve Guttag]

It would be nice if there were more practical means of getting light engines serviced. Common issues (that are growing):

• stuck pixels (either on or off).
• formatter failure (typically, results in horizontal stripes on screen of the affected color)
• deep cleaning. Seriously, if you get a light engine cleaned, you can get 20-30% more light. You'd be amazed how much light is lost on a dirty light engine.

One can clean quite a bit of the optics of most light engines...but once one gets to the prism, normally, except for Fandi here, that is as far as most (including me) will go.

[Christos Gartaganis]

Kudos to Fandi for his courage and patience. I'm still interested in knowing how many hours he invested in taking apart the DMD panel from the prism, cleaning it, and putting it back together.

[Ryan Gallagher]

I got curious if there were any workbench "portable" clean room type things that would be handy for such services if anyone wanted to specialize. Apparently there are some for phone repair techs that are about lunchbox size, I was hoping for a collapsible tent similar to a photo light box or film loading gloved box, but these are fun too. Maybe Fandi has a calling. ;-)

https://www.amazon.com/dp/B0DP416XJJ

bench_Clean_box.png

[Christos Gartaganis]

Maybe a professional laminar air flow cabinet like this could help with similar tasks. I bet there are cheaper options available on the internet.

https://www.biobase.cc/Horizontal-Laminar-Flow-Cabinet-pd526253598.html

[Marcel Birgelen]

Those bigger laminar flow cabinets are used by data recovery firms too, those who disassemble failed hard drives to extract the platters. They work and should be sufficient for something like light engine repair. I'm not sure if I'd trust one of those AliExpress "laminar-flow-hoods" with a light engine, it will be hard to keep all the elements you need for a repair "under the hood".

Louis Rossmann, a strong supporter of the "Right to Repair" cause posted an interesting video about the efficacy of laminar flow hoods a few months ago:

[Marco Giustini]

I suspect that when you have a big blotch on the screen, some probably invisible specks of dust might be the lessen of the two evils. The optical path will focus on the DMD, the protection glass is further away so only large contamination will be seen.

[Ryan Gallagher]

Yeah I was sharing the ali-express-esque bench top idea unit for the actual part cleaning if removed, there are a fair number of choices in "semi portable" bench top varieties, it does nothing to protect the part or the whole engine while disassembling unless you step up to something the size of what Louis has. Doubtful a portable option exists there. The most maybe-portable larger variant saw was 40x40, with the frame constructed from T-slotted extrusions that could in theory be broken down a packed out.

If you wanted to put the whole projector in one there appear to be 2 to 6 person inflatable "tent" things, but prohibitively expensive for a "tool", the air handler unit is considerably larger too, but carriable it seems (has handles anyway).

https://www.antistat.com/wp-content/uploads/2025/01/615-1003-US-Monmouth-Cleanroom-Tent-Sizing-Chart.pdf

Amusing aside, Louis, being in Austin... I had a path crossing event just the other day. He was crossing town lake on the pedestrian bridge going the other way... I was on my bike but it registered it was him about 10ft past him. I didn't stop or yell anything, he was on the phone... but of all the youtubers to just "recognize" out on the street he was my first, and an unlikely one for most. His shop is closer to my old neighborhood (near the university) than where I am now.

[Marco Giustini]

To be honest, I'd be more concerned about torque and contamination on the contacts of the DMD. But maybe they make this appear much more critical than it is. Chances are that most of the "bad" engines I've stumbled into over the years could have been fixed by removing the formatters, clean the contacts and re-assemble everything back. Who knows.