CurtPalme.com Home Theater Forum

[Revox]

Hi, i thought that i got finished my working on the CRT's with the setup of my M 8500. Now i got a NEC PG 9 from my university for a donation of 200€. Tubes are perfect the complete set has got 800 hours on its clock.
My first question is about the fans. I got the Pj on Wednestday and i'd like to order Fans now.
How many Fans are in there?

I'am thinking about swapping the Lenses to my M but the adapters are realy expensive. Then i put HD 6 on the NEC.

My M has got coloured glykol now so i'll lost brightness.

[kschmit2]

Leave the fans alone. They are of highest industrial grade standard. The only viable replacements with the same durability would be Papst fans with the exact same CFM-rating (measured - not marketing-ratings like all of the PC fans). You would not gain any noticable reduction in noise though, since most of the noise comes from air turbulences inside the chassis. Reducing airflow by using low quality fans would ultimately kill the PJ.

Kai

[draganm]

don't waste your money by dumping it into the 9PG for new fans or anything else. the M8500 and 9PG are are at opposite ends of the the intermediate Projectors rankings. Put it on CL or Videogon and use the money to upgrade the Marquee. Lots of things you can do to move that machine up to another level of performance besides lenses.

[Revox]

Oh, that sounds not realy good!
As i understand, the heat dissiapation depends on the scanrate. When the set is desinged to work at 35°C there will no problem of using a temperature control?
There must be a way to noisereduce the set (mabe with more Fans?). Is it is now it's not possible to watch a film.
At the end, i'd like to reoffer the NEC (calibrated and focused well).

In my M 8500 only the focus Module runns a "hot" with noise reduced fans.

[draganm]

[Revox]

It's hard to touch the headsink for more than 5s.
My problem is that a loud CRT is senseless for me

[Nashou66]

[Revox]

Ok, i'll work on the focus Module by installing a 4th Fan. There is not so much space left at the top.
The holes of the 3 12cm Fans are so small, i cannot understand the engineers of the M at this point.
With the original Fans (with changed LVPS Fans) the M was really noisy for me.

My experimence with "hot" hardware was good until today. My CPU and all of my PC (especially the power Supply) runs realy hot for a two years now. I don't expect 20000 Hours out of my 8500!

[Nashou66]

Thise fans do not have enough CFM or static pressure not a good fan for the LVPS or the bellys!!!!

I use these on the LVPS and they are 44CFM and have good static pressure also( H2o/mm)

http://www.directron.com/uc12eb.html

Features:
Long life.
Removable blade.
Super quite (17db).
RoHS Compliant.
Exclusive ENLOBAL bearing with magnetic-barometric design to run friction-free and noiseless.
Nano-technology composite for lowest abrasion and extreme durability.
Detachable fan blades can be cleaned.
Best wire management and 3 to 4 pin adaptor.

Specifications: Bearing Type: ENLOBAL Magnetic Baraometric Bearing. Fan Speed (RPM): 1000RPM.
Air Flow (CFM): 44 CFM. Noise Level (DBA): 17db. Rated Voltage: 12V DC. Rated Amps: 0.20A.
Power Connector Type: 3pin / 4 pin adapter. Dimensions: 120x120x25mm.

Yours are only 37 CFM way to low for the LVPS and also the Belly's I think need closer to 50CFM if not mistaken maybe the mid 40's. and yours are 20 db a little louder the Original fans are the about the same, Id put them back and just use some isolation foam in the chamber and to isolate the fan from the case. do the same on the LVPS.

Athanasios

[Revox]

You think I am kidding saying "when the air comes out is not hotter than 35° it's ok ".

[draganm]

the fans in the pictures are junk. You will have soon have a broken Marquee

[Nashou66]

measure the temp of the heat sink, who cares about the air? or measure the temp of the actual amps on the HDM and the FCM and then the back heat sink. the way the cooling system works on the marquee was a very well thought out design.

First you need enough cfm for the LVPS because it also pulls air through the HVPS, if not the HVPS could be damaged.

Second the case should be sealed, closed that is. the static pressure needs to be there, so running a marquee with out the covers on can cause certain sections to over heat
despite what seams logical.

Third the Belly fans, they are located to pull air from the sides and the back through holes near the CLM and VIM and then up through the fans which then push the air into the HDM and FCM and into the plastic covers of the tubes. The plastic covers act as a channel for the air to move back over the VNB's then the remaining air gets pushed out and over the rear heat sink that hold the CVA and VDM. that path has to stay intact and not be obstruct or caused to loose pressure, so a low pressure fan will not have enough power to get the air all the way tot he back heat sink.

Athanasios

[Revox]

Ok that really helps.

But give me some more information about the 3 12cm Fans. They didn't have a air connection to anything else than the bottom hole. -> There it is, i removed the VIM and then it comes into my eyes.
My M is floorstanding.
I removed the cover of the headsink, it suitible for warm fod (oh my english, not food).

The headsink of the HDM is realy cold, like 40°C.

So ill install another fan in near to the HVPS. The cover of the necboards is not noticeable war, (i only use 1080i). And an Additional Fan for the Cards.

[Nashou66]

I think you should keep the original belly fans or look for the pabst fans that most here replaced them with. I know there is a thread about it here or on the AVSforum site. I think HK-Steve was one of the first to do the fan mod . Some one else cut the tray that holds the belly fans and added one more, they used nuctura fans I believe . Thing is you have to have good pressure, CFM sometimes means nothing if they can't also produce good static pressure. for the Belly fans you can do this test, put the original fans in and tape one end a strip of paper maybe 1cm wide and 10cm long to just go over the hole on the FCM or HDM where the air comes out.
Turn on the PJ and measure how high the paper's loose end is lifted up. now switch to your fans and do the same, is the paper lifted the same amount? if so then I think you will be ok. If you want to go further with the test put it over the holes on the metal cage for the VNB's too , that is where it might not be as good.

I would not add another fan near the HVPS since you will add more noise, just look for a 120 mm fan that will have close to 45 CFM and is lower than 2o DB. the original I think was 25-30 I can't remember for sure.

teh fans I use are so quiet i have to get very close to the PJ when it is off to see if its plugged in.

You also need to make a step down power supply for the 12VDC fans since the marquee uses 24VDC, this will make the fans burn out faster or fail.

look on my Maintenance thread I have the schematics there for the power supply.

Athanasios

[David_Web]

Just a question to be clear.

Should the outer two holes under the belly fans be plugged?

I don't have the bottom cover on mine but I could install it.

[Nashou66]

[Revox]

To read this is very interesting. I didn't thought that the cooling concept was that "perfect". I removed the cover of the headsink in the back for a better convection cooling, but i was wrong thinking that it's only convection cooled.
The 12V Fans are running at 12V (not with a stepdown, a 7812 with a little heat sink is enought).
I think, that the airflow after the HDM and the Focus module in the case can't be that much.

As my conclusion:

1. When the Heat sink in the back is 40°C warm (or so warm that heating my feet isn't confortable anymore) its enought to be convection cooled. When it isn't enough i put thin 10cm Fans on it and run them at 6V-7V, ore two 12cm Fans run at 5V.

2. The airflow at the Focus Module is not enought when it reaches over 50°C, the 12cm Fan at the bottom of this board must run faster -> That is my problem Zone!

3. For a better airflow throught the HVPS i must close a few holes in the front, install another Fan or run the fans with fullspeed (that's soo loud). Is there no posibility to remove a cover for better airflow?

4. I'll install another 3 Fans the behind Neckboards running at 6V.

[Nashou66]

[Revox]

I am reading this thread right now ...
All what i know working with my PC is, that adding more fans run very slow is always a noise reduction.

I think 29db is much to loud for me, i am very sensitive and a Film with that noise added is not visible for me.
I had problems with my IBM X41 notebook with a 1,8 4200 drive that was too loud to work at (no fan noise at all), so i bougth a expensive SSD. When my PWM controlled CPU Fan (12cm) run at 1000U/min my PC seems to be very loud for me (my Power Supply work fine with a Fan run at 5V)

I am very glad that you told me so much about the concept and it helps to mod my setting in the moment.


Keep in mind that's "always" cold in Berlin even more at the floor.

[Nashou66]

Ok Good luck, I hope you find a solution. Now go to bed!

Athanasios