CurtPalme.com Home Theater Forum

JorisS · Joined: 18 Jun 2007 Posts: 160 Location: Uppsala, Sweden

Hey all!

I'm currently digging into the pj, I want to swap out the noisy fans for quieter ones. I'm aware of the importance of proper cooling and all, but am fairly convinced that in the cold environment I'm using it, I'd be fine with low dB fans of good quality and decent CFM.

I've managed to remove 4 Panaflo fans so far, those were the easy ones. Now I'm trying to figure out how to get to the three below the tubes - I've never really dug into the PJ so I don't know how to get to these. I'm guessing I'll have to remove the tubes, just wondering how - preferably without irreversible damage Smile

Also there are some smaller fans down there, cooling the front unit/part - I'm guessing these little buggers are quite the noise engines too, so I'd like to know how to get to those as well.

Enclosed two pics, feel free to grab a copy and go wild with paint or whatever, for indicating how to proceed. Or, if there's a clear guide out there somewhere, I'd be much obliged if somebody could provide a link!

Cheers
//Joris, Sweden

Teh pics (click for larger version - then click the pic in the new page again for really large version):

**Curt Palme** · Posted: Fri Mar 27, 2009 6:15 pm Post subject:

http://www.curtpalme.com/NECXG_Layout2.shtm

Seems like no one reads the website any more... Mr. Green

JorisS · Joined: 18 Jun 2007 Posts: 160 Location: Uppsala, Sweden

JorisS · Joined: 18 Jun 2007 Posts: 160 Location: Uppsala, Sweden

Ok that wasn't too hard, so now I removed the tube neck from the red tube - which screws are to be loosened/removed in order to get the tube out of place? Anything particular to take care with/of? I'd prefer not to unplug all cables and forget how they were mounted to begin with, is it possible to lift the tube out of the way and put it on top of the chassi somewhere while getting at the fan(s) ?

MikeEby · Joined: 24 Jun 2007 Posts: 5237 Location: Osceola, Indiana

The fan on the green neck board is a total POS. I wired in a PC fan held in with some velcro. Just that one fan made a huge difference. I didn't want to effect reliability so all my other fans are stock. A ducted hush box is the best choice IMO without effecting the reliability of the projector.

Mike

jarseneau · Joined: 06 Nov 2007 Posts: 323 Location: WI

Another great gude for XG tube replacement can be found here.

Mark_A_W · Posted: Sat Mar 28, 2009 6:32 am Post subject:

Assuming the main fans are in good order, all I would do is change the green neckboard fan, and solder a 100ohm resistor in series with the Deflection board fan (it whines).

I would leave the main fans alone.

And build a well-ventilated hushbox Smile

JorisS · Joined: 18 Jun 2007 Posts: 160 Location: Uppsala, Sweden

Mark_A_W · Posted: Sat Mar 28, 2009 12:07 pm Post subject:

You are aware that the fans in the XG are not standard PC fans, and it's a locked rotor sensor not a tacho?

JorisS · Joined: 18 Jun 2007 Posts: 160 Location: Uppsala, Sweden

You mean that the yellow wire is sensing if all fans are spinning, not adjusting RPM depending on temperature or so?
If so then yes I'm aware of that. If no then please elaborate somewhat Smile

Does it require a very specific RPM signal? I think I read about this when I did a small mod earlier, replacing some resistors - one could effictively 'trick' the PJ by keeping one original fan at 100% and splitting its sensor cable to the other connectors?

JorisS · Joined: 18 Jun 2007 Posts: 160 Location: Uppsala, Sweden

Just removed the power supply unit, and discovered some kind of oil-ish liquid in a small stain underneath - wondering if this could be glycol, and if it is, where the heck it came from? I can't see any kind of leak from the green tube (under which it was):

Curt, if you're reading this: do you keep any kind of log of serial numbers or anything of all projectors that pass by you? While digging and enjoying myself I noticed that the neckboards have been written on (red/blue/green) and a bunch of the wiring is labeled with a small piece of paper inside a double layer of tape - don't know if this is how these machines were put together and delivered or if that all are remains of previous owners?

Anyway, as far as the pics are telling, I can't see any signs of leaking from the tubes, so wondering if it IS glycol and if so, where it came from. Perhaps a tube has been changed and the pj wasn't cleaned properly?

On a sidenote, the FBA08T12H type fans sound like a jet engine by themselves - swapping these out alone should do a lot of difference.

//J

KennyG · Joined: 10 Feb 2007 Posts: 254

I am down to three fans in my system, the two power supply fans and the high voltage board. (which I've slowed down)
However, the reason I can get away with this is that I have a 100 cfm fan mounted up in my attic that pulls air through a plenum that covers all the venting on the top of the XG...and it has dropped the operating temp of everything mounted near those vents by 25 degrees.
If you look at the XG's construction you'll see that all it's heat producing components are mount on heat sinks that are position near the top (if mounted on ceiling) all around those open vent holes. If you build a plenum to seal that whole vent area to a single remote mounted fan, you can remove about 12-15 db of noise, then install in-line resistor in the three remaining fans, and you'll drop that noise another 3-6 db
It may have been covered, but you can cheat the fan logic on all fans removed by grounding the yellow wire.
I would have to look at my notes, but my remote attic fan is turned on by the pj. When I turn it on, it sends a 15 vdc signal to a relay that controls 120 vac to the fan...then I have a pressure switch (set in "H2O vacuum) that kills the system if I lose air flow.

JorisS · Joined: 18 Jun 2007 Posts: 160 Location: Uppsala, Sweden

Thanks for the info Kenny, sounds like a nice quiet solution you got there! The way things are looking now I'll probably have the projector operating on the floor though, not ceiling mounted -that makes it harder to work with a solution like yours Sad

As for the yellow wires, what was that? Can one simply tie them together and ground them and everything will work fine? (provided one keeps an eye on the fans doing their work properly, ofcourse)

I've managed to get to all fans except those under the tubes - not too keen on pulling these out for those fans down there. Also, I'd rather come up with some own-made design and mount three 120mm fans there instead of the 80mm panaflo's. That would mean better air flow at (much) less noise. Plus I have some 120mm Noctua fans idling around here - nice and quiet beasties those Smile

As for the 'glycol' - could that simply be a thermal paste residue that's there to improve heat transfer from the power supply block to the chassi?

//J

KennyG · Joined: 10 Feb 2007 Posts: 254

KennyG · Joined: 10 Feb 2007 Posts: 254

You know, with regard to removing fans, I had a few pictures floating around here a couple years ago.
I also modified the chassis by opening up the area above the two outside crt amps (neck boards) and closing up a couple areas that didn't need so much air movement.
Here's something you could do, and it would work just as well as my system.
You could build a shallow plenum over the vent openings in the bottom of the XG...say 3-4 inches tall, then mount those two 120mm fans your talking about in the top of the plenum.
Now what you have is a box sealed to the chassis of your XG, with two fans in it's top (or actually bottom)
Then cut an opening big enough for the plenum to sit down into, on the table the pj will be sitting on...I would also build sides on this table, and space them with an opening, all the way around, about 1" above the floor.
Then I'd line the inside of the pj table with acoustic foam.
You could use some sort of rubber weather stripping to seal the plenum walls to the table cut-out, this way hot air and noise will stay below, and exit out that 1" opening all the way around the bottom of the table. If your room is carpeted, then much of that exit noise will be soaked up by it.
Inside the table, I'd also install a couple cross braces, made out of 3/4" plywood, and perhaps 10" wide, I'd mount them vertical and adhere acoustic foam to both side of each brace...this will farther reduce noise.

JorisS · Joined: 18 Jun 2007 Posts: 160 Location: Uppsala, Sweden

You know what, I think I should invite you over to my place Laughing

Interesting that the tubes don't get warm really according to the tests you did - the three fans below them (when standing on the floor) are blowing air towards them, but also from the bottom. I would agree with you that they probably provide circulation, if indeed the bottom part is the part where the hot stuff is (surely the cooling bodies are there!). In a way it's silly that if the bottom plates get so hot, to push that air onto and across the tubes, if the purpose is to cool the tubes.

So if the purpose is mainly to circulate air, the fans could pretty much be anywhere lying on the bottom as well, instead of suspended in midair. Perhaps not quite as effective though.

I'll give it some more thought. Cheers for the tips and help so far!

On a sidenote, I know that glycol isn't the same as thermal paste - what I meant is that I found something somewhat sticky between the housing of the power supply and the bottom of the chassi, which I wonder what it is - either glycol or thermal paste of some kind. Hoping for the latter Smile

KennyG · Joined: 10 Feb 2007 Posts: 254

I have owned 5 XG's, one Marquee 8500, a Barco 808, and a Ampro 3500 (sharpest picture of all) Of all these projectors, the XG's is the worst cooling system...it's air flow makes little sense.
The others use tunneling or pressurization., but the XG pulls air in through the side fans, moves that air in all directions via the other fans in the tube cavity...then let's it thermally convect out via natural air flow created by the heat sinks in the bottom, heating the air and letting it gently raise out, simply because hot air raises.
If you use a fan to mechanically pull air over those heat sinks, it creates a more efficient cooling system, and as I said before, that drops the temp across all those H-sinks by about 25 degrees F.

JorisS · Joined: 18 Jun 2007 Posts: 160 Location: Uppsala, Sweden

I'll get creative and put my experience from the computer (water) cooling to use. However, the problem is that we'll be moving in a week or 4 and in our current apartment I really do not have the space to pull out the tubes and have them lying around under a longer period. So I think I will have to put this on hold for a bit, till we have settled in somewhat in the new house. Perhaps I could try and remove those three 80mm fans and work on a mod to accomodate larger fans.

Appreciate the info, as I thought those 3 fans were important for cooling the tube necks/hardware directly where they're aimed at. Indeed it seems to be rather silly to not have some fan actively blowing out hot air, imho. Perhaps reverse the order of things, draw in cool air from the bottom (in a floor setup), have the internal circulation as is, then point those side fans outwards instead. No real options at the top as the deflection board is pretty much cutting off any flow upwards. There seems to be a rather large opening at the side of the projector opposite where the HT leads are - there's a piece of metal there that seems rather useless and might be removed, to allow for a 120mm fan to be placed there....

Interesting Very Happy

KennyG · Joined: 10 Feb 2007 Posts: 254

Bert Randolph · Joined: 03 Jul 2007 Posts: 81 Location: Germany

Very interesting thread.

I use three 12cm-fans at the top of the XG to suck all the hot air out. This really brings down temperatures a lot and you can slow down all the chassis fans.

My concern now is with the two fans in the power supply. These were the most annoying sound sources in the PJ after the first mod. A high pitched whining. What I did was adding a resistor to those two, slowing them down somehow. To compensate I to cut a circular hole in the power supply and added a 8 cm fan there, allowing better air intake.

Did anyone do some real temperature measurements in the power supply? I only have a very simple probe which is not very usful for this purpose. I am just not sure how critical the cooling of the PS is - what do you think?

Daniel.