JVC D-ILA Pink\Magenta Stripe Fixed - X35 in this case Pictures of inside optical block

ChuckMountain

Distinguished Member
There are a lot of threads on the net about issues with a variety of JVC D-ILA projectors having coloured stripes at the edge of the screen appear over time. There are a variety of reasons given and some fixes suggested but in this thread I will show what I found on a repair of an X35. (It's not for the faint hearted)

Thanks to @Cocksure for donating his projector to this worthy cause :clap:

Depending on the orientation of the projector these typically appear at the right hand side for ceiling mount or left if shelf mounted. In this case, mine is shelf mounted and has a magenta/purple/pink stripe down the left had side, most visible on a white background.

IMG_1407.jpg


The cause in this case is a misalignment of the yellow mirror in the optical pathway. There are some suggestions on the web.

The main optical block removed

IMG_1414.jpg


Below are the mirrors and their adjusters, the three metal plates with two black screws.
IMG_1415.jpg


The mirrors some of which are dichroic are locked in place by two pieces of metal which are glued together to prevent further movement. There is marginal adjustment allowed because of the black pegs, not enough to cure it. Removing the pegs might allow a bit more movement but the screw holes are round and so only allow a tiny amount of movement.

Blue Mirror is Top right hand, yellow mirror is bottom right, Red\orange ? is bottom left.

The way to fix it is to break the glue bonding the two metal pieces, adjust and reglue. The problem is that to do the adjustment you need to do in place\powered up with the various cooling in place. Only the top blue mirror is easily adjustable, the yellow one is harder but not impossible. The red one is behind a circuit board. What I imagine in the factory is that the optical block is calibrated in an adjustable harness the mirror adjustment is set then glued to prevent further movement.

The mirrors particularly the red one are very thin and though I didn't break them I think it would be easy to do.

A fraction of a millimetre movement is enough to resolve the problem in some cases. I then reglued using No Nails as its removable and I had it to hand.

A few comments on other cures on the web:-

1) Glue - failure - not convinced about this, the glue was certainly intact on both mirrors adjusters and there was no obvious movement. Expansion and movement over time of parts could cause the issue

2) Blowing hot air into it - you would have to pretty lucky to have this cure it

3) Aluminium tape - this will work but effectively you are substituting the tape for the glue and using friction to hold the mirror adjuster in place. With no glue the adjuster moves "freely". This may cause excess pressure on the mirror.


When you remove the adjuster, by taking off the black screws you may well pull the mirror out of the other side holder as well. These are delicate.

The projector has done quite a few hours (~4,000??) and has collected a lot of dust, at the same time I stripped down what I could of PJ and the optical block and cleaned it.

Before I started (rather dusty :p)

IMG_1385.jpg


Was it a good idea taking it all to bits
IMG_1405.jpg


The optical block exposed - delicate mirrors, dusty o_O

IMG_1418.jpg


Dusty mirror

IMG_1416.jpg

Optical block after cleaning

IMG_1421.jpg


What happens if you break the blue mirror glue :facepalm:

IMG_1423.jpg


Fully cured (though convinced there might be a yellow tinge at the top right)

IMG_1422.jpg


Although there is different exposure in the last 2 pictures, the PJ is significantly brighter than it was when I first got it.
 

ChuckMountain

Distinguished Member
There is still crap in the optical pathway, hoping its in the the lens as that is not easy to disassembly as can be seen by the blobs when the focus is very far off, they completely disappear when focused properly and wouldn't have noticed if I had not tweaked the focus when cleaning it and restoring a lens memory

IMG_1432.jpg


And here is something random on TV, picture looks good, problem solved :clap::clap:

IMG_1429.jpg


The bulb has around 3,500 hours on it but still looks really good :D
 
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Cocksure

Well-known Member
Boy am I embarrassed about the level of dust I put on it :blush: still does show how well built the jvc's are :)
 

linnasak

Active Member
So would this be a worthwhile fix by say JVC, when out of warrantee, how many hours did you spend? Would pay few hundred to refurbish my hd950 if had some comfort it would not end up US. Balance I think is risk of write off trying to cure versus leaving as is with fault masked with reduced image size.

Regards
Kevin
 

ChuckMountain

Distinguished Member
Boy am I embarrassed about the level of dust I put on it :blush: still does show how well built the jvc's are :)

Yes I must say the are well built and designed well (apart from this defect). There was so much metal braid\grounding tape in it, the wiring connectors are well made and reliable. The only thing they don't have is much of an air filter. A wire mesh one at the bottom for the optics cooling, but its a not a particularly fine mesh.

So would this be a worthwhile fix by say JVC, when out of warrantee, how many hours did you spend? Would pay few hundred to refurbish my hd950 if had some comfort it would not end up US. Balance I think is risk of write off trying to cure versus leaving as is with fault masked with reduced image size.

US?

I don't think JVC will ever offer this method of fix as its too intensive\risky, unless they do a servicing offering as well.

Using my picture time stamps, I started the strip down on Sunday afternoon and finished last night, probably spent 15 hours or so maybe a bit more. There was probably some wasted time and repeated steps I did, so doing it again it would be quicker.

However, this was a full strip down to the point everything got removed and cleaned by a combination of compressed air, plastic parts were removed and washed to remove some stains, optics were cleaned with lens cleaner and microfibre\kitchen roll\ear buds.

The before and after brightness and picture quality improved considerably though from the clean, noticeably so even though the bulb is near to end of life.

If you just wanted to realign the mirror for a magenta stripe then you could probably get that realigned in around an hour of labour. The glue will snap and allow movement of the mirror in situ, you just need to re-glue it. It shouldn't break the mirror as the movement to break the glue will be in the range of adjustment of the mirror if that makes sense.

Some people in the US have had a proper camera shop repair them as it is possible. Whether they would clean it etc to the same standard as you do your own things, who knows? Also if there is any risk of movement for shipping and movement.

JVC will get an optic block and just swap it out, it doesn't require any specialist tools or risk, but it is mega bucks. I don't think they would want to do the clean or be necessarily trained like an optical place would be unless they have a specialist repairer or 3rd part.

I can't imagine you being able to get the internal parts if you shattered a mirror and that's the problem.
 

Cocksure

Well-known Member
@linnasak from what I read before I decided it was to much for me is that jvc just change the optical block which is not financially worth doing. Hence the posts on diy method.

There are 3rd party companies that repair jvc projectors, but whether they would be prepared to do what jvc won't you would need to enquire.
 

ChuckMountain

Distinguished Member
@linnasak from what I read before I decided it was to much for me is that jvc just change the optical block which is not financially worth doing. Hence the posts on diy method.

There are 3rd party companies that repair jvc projectors, but whether they would be prepared to do what jvc won't you would need to enquire.

And also whether they would offer a warranty of sorts even if its 30 or 90 days etc.
 

ChuckMountain

Distinguished Member
Nice work!
I think this excellent work probably settles the claims that these have a "sealed optical path". Sure, sealed from the main PJ PSU / lamp cooling airflow, but the optics clearly aren't "sealed" in the way that people might hope they are.

Definitely, these don't have sealed optical paths, would be nice if they did. I am surprised that cinehome said they did.

In the case of the X35, there are 6 fans, looking at the lens air is drawn in from the back on the left hand side and at the front on the right hand side. Separate air is drawn in from underneath, through the only filter for the optic block, imo the filter isn't great

1) Front right hand fan blows air over the PSU
2) A blower fan also pushes some of this air over the D-ILA driver boards
3) Exhaust fan from PSU area
4) A blower fan for the optical block, which basically cools the D-ILA chips and pushes some air into the rear optics
5) A blower fan for the bulb which draws from the main internal body, this would include the exit from 2 and 4
6) The exhaust fan which pushes air out the front left

on the other models there is also an Iris fan.

Additionally the front optics are not sealed either, there is a hole where dust can enter in the middle of the lens.
 

jfinnie

Distinguished Member
Definitely, these don't have sealed optical paths, would be nice if they did. I am surprised that cinehome said they did.
I make a point of calling people up on it whenever I see it written as all the evidence says it is garbage claim - same goes for most DLP devices people here buy. Yet it still ends up all over buyers guides. Crucially NONE of the makers out there of actual projectors actually make this claim publicly from what I can see.

I think a lot of people make the erroneous leap still that because a lot of the imaging device heat could be removed from the devices from the rear as the light is reflected off the devices that there isn't a need for air circulating around the optical block.

I'm certainly not knocking JVC projectors - I have one and love it - but I just hate seeing falsehoods regurgitated.

From what I can tell the key dust-busting difference with these projectors vs the competing techs (and what helps the dust become less visible) is probably that the imaging plane is physically distant from where dust can actually land (the D-ILA device has a glass top). This distance means that if you've focused accurately on the imaging plane the dust ends up very much out of focus. It seems like the JVC units have significant advantage here over devices where both sides of the panel are open.
 
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ChuckMountain

Distinguished Member
The thing for me was that the dust layer was fairly consistent so I don't think it would change the image or be noticeable in say patches. It would however alter the overall brightness and basically lower it. Definitely a night and day difference between the cleaning.

Here is the last mirror which is dichroic .
IMG_1420.jpg
 
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jfinnie

Distinguished Member
I think the dust can gather in several places.
The mirrors >should< just cause dimming as they're used to split the light before the D-ILA chips, unless it were only on one part of the mirror, then it would be a uniformity issue.
The prism or D-ILA chip surfaces would be my bet for the dust you can see in the photo you took out of focus. Or maybe the back of the lens.

Using a piece of paper close to the PJ with a black screen shown I can see my dust spots look to be in at least 3 different focal planes (without adjusting the lens focus, moving the paper forward and back), so probably in 3 different locations.
 

GaryB

Distinguished Member
@linnasak from what I read before I decided it was to much for me is that jvc just change the optical block which is not financially worth doing. Hence the posts on diy method.

There are 3rd party companies that repair jvc projectors, but whether they would be prepared to do what jvc won't you would need to enquire.

Sontec offer this service and have done for a few years now. Think I mentioned it in the other thread. It used to be around £200 +VAT & carriage.
 

ChuckMountain

Distinguished Member
Sontec offer this service and have done for a few years now. Think I mentioned it in the other thread. It used to be around £200 +VAT & carriage.

Yes I wonder if that will just be a mirror realignment or a full strip and clean, I suspect the former though.
 

ChuckMountain

Distinguished Member
I think the dust can gather in several places.
The mirrors >should< just cause dimming as they're used to split the light before the D-ILA chips, unless it were only on one part of the mirror, then it would be a uniformity issue.
The prism or D-ILA chip surfaces would be my bet for the dust you can see in the photo you took out of focus. Or maybe the back of the lens.

Using a piece of paper close to the PJ with a black screen shown I can see my dust spots look to be in at least 3 different focal planes (without adjusting the lens focus, moving the paper forward and back), so probably in 3 different locations.

Thinking about it now I probably could have cleaned a bit more but wasn't sure about the D-ILA chips, looking at now they do have a protective glass cover but I didn't want to mess with any alignment. So lost my nerve and probably thought quit whilst ahead, also I am hoping less dust into the last bit as the last condensing lenses appeared a bit less dusty. Now I am wondering ...

Below is a diagram of D-ILA optic path and the area inside the orange ring I cleaned.
D-ILA Orange.png

All the X35 integrator lenses are after the mirror.
 

jfinnie

Distinguished Member
Thinking about it now I probably could have cleaned a bit more but wasn't sure about the D-ILA chips, looking at now they do have a protective glass cover but I didn't want to mess with any alignment.

Really useful diagram. There's no point stressing over it really is there; at the end of the day if it disappears when focused correctly it probably isn't causing significant harm to image quality, though it would be annoying to see them when the unit is de-focussed. I reckon there must be a good chance some of the dust is on the polarisers in front of the D-ILA chips.

Annoyingly JVC don't break out any of the optical block parts as spares in the X3 service manual I have here. Sanyo (via Panasonic now) were quite happy to supply individual polarisers etc - I even bought the "cinema filter" part from a higher model to have a play with once.
 

ChuckMountain

Distinguished Member
No, not stressed just curious, but curiosity killed the cat or this in this case the PJ :)

Just realised I don't need to touch the mirrors again as they are in a separate section so it could be worth having a look :)

I suspect that JVC had a separate manufacturer for the optical block and its only available to them as a complete unit hence no split out of parts.
 

jfinnie

Distinguished Member
I'm sure at least some of it will be down to the difficulties in training people, effort in documenting processes, and the much higher requirements equipment and skills-wise for servicing projectors down to that level, plus an effort to control the quality. Plus if jigs are required then those jigs have to be replicated around the world, and updated every time a new model comes out. These might be very costly setups given the tolerances involved.

It is a shame for us meddlers though!
 

John Woodcock

Active Member
No, not stressed just curious, but curiosity killed the cat or this in this case the PJ :)

Just realised I don't need to touch the mirrors again as they are in a separate section so it could be worth having a look :)

I suspect that JVC had a separate manufacturer for the optical block and its only available to them as a complete unit hence no split out of parts.
I was wondering if i should send my X35 as the red-red-amber light has started to come on, and i appear to have missing pixels just right of the centre of the screen but not seen if you sit on left side, I believe it could be a board issue as a friend of mine has the same pj, pj done 2900 hrs.
 

ChuckMountain

Distinguished Member
I was wondering if i should send my X35 as the red-red-amber light has started to come on, and i appear to have missing pixels just right of the centre of the screen but not seen if you sit on left side, I believe it could be a board issue as a friend of mine has the same pj, pj done 2900 hrs.

Send it where to JVC, Sontec (or me ? :cool:)

The lights flash different signals depending on the fault. Usually the number of amber flashes and the status of the middle give the fault according to the service manual. I have a copy of the X3 which is very similar however a few people report a 5 flash amber which isn't in the manual.

Is there a particular sequence?

As for pixels not visible that seems quite strange, particularly if it varies with sitting position.

Do you have any test screens, solid red, blue, green etc. that you can test to see if it is more noticeable on one rather than the others. The light path splits into 3 so in theory if you got a defect pixel that would only show on one. If the driving board was faulty its strange that it affects it in that manner. It could be crap on the optics but do you have any photos?

Did your friend's have a board issue ? I can't imagine it would be a cheap fix either as the boards for most components are expensive.
 

Barcoing Mad

Well-known Member
Thank you for this thread. Interestingly (for me at least), I had the dreaded pink stripe, but it faded. I'm guessing that whatever physical deviation caused it later wandered back in the right direction.

From what you unearthed, however, it would seem that a good clean would be in order....
 

Barcoing Mad

Well-known Member
Rather begs the question over what will happen to laser based PJs: not much point in having a light source that lasts for a few tens of thousands of hours, if the thing's ancillary optics are gunked up in roughly the same period that an ordinary lamp lasts.
 

ChuckMountain

Distinguished Member
That's true.

Having stripped it down though, I don't think there is any reason why you couldn't have sealed the optical pathway completely. The hot spots are clearly the bulb and the D-ILA chips. The latter have heatsinks on that are what the air blows over anyway. The bulb itself is cooled and the rest of the thing is a huge bit of machined metal.
 

corrado kid

Active Member
Interesting thread this. Can I ask did you have a service manual for the strip down? And also how much do you think could be cleaned internally without major dismantling ? I have an x35 which has no obvious picture issues but I don’t think it’s as bright as it used to be despite a recent new bulb, and might benefit from a clean!
 

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