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Discussion Starter · #1 ·
Last week our G11 failed. We sent it back to JVC for repair. We heard back from JVC yesterday, so I thought I'd share a couple of things.


First, JVC said the failure was heat related. In my on-going quest for better sound we had placed the G11 into a Whisper Flow hush box. Inside of the hush box we had placed 2" acoustic foam. It ran this way for about a year without incident. There are two fans that operate constantly inside of the hush box.


About two months ago we replaced the standard JVC bulb with a replacement bulb from the company several have used on this site. This bulb I was told was a 500W bulb instead of a 420W.


We use the HT , on average a day or two per week.


Now I wonder if this replacement bulb in our hush box with foam caused the failure? That is, if the new bulb operates at higher voltage, I am assuming higher voltage = higher heat?


Anyway, thought this might be useful to some others on the forum.


Chuck
 

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Discussion Starter · #3 ·
Dave


The foam was on all interior surfaces of the Whisper Flow. We have two fans now. I have a third fan but have not yet installed it.


No one has replied as yet to the question that if you have a 500W bulb obtained from Ralph that am I correct in assuming that the higher wattage of 500W also equates to higher heat?


It is roughly 20% higher in wattage, so would that mean 20% higher in heat? Maybe the heat would be higher?


Chuck
 

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I seem to recall someone recently posting that the 500W bulb resulted in a 3 degree temperature rise. I do not recall if it was the internal temperature of the projector, or the temperature of the exhaust air. Perhaps a search of the archives can find it.


Steve
 

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Hi Chuck,


I think with the added btu's and 2 inches of foam on the discharge size may be the problem. Here are a few suggestions to solve:


1. 2 inches of foam on the discharge side of the projector is overkill. I recommend reducing the thickness to 1" on discharge side only. The reason behind this is to create additional clearance from the projector and eliminate backdraft.


2. The new WhisperFlow Projector Hushbox II design eliminates the bottom baffle arangement but we add an intake fan, right side facing hushbox, for the G-series, 8 inches from the front faceplate and 3 inches down from the top. By using this arrangement, we were able to lower fan speeds while increasing cooling. I suggest that you add your spare fan for additional cooling. Please feel free to call me anytime to help increase the performance of your existing hushbox!


All the best!!


Dave
www.whisperflow.com
 

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Quote:
Originally posted by ChuckTraywick
I am assuming higher voltage = higher heat?
yes and No. the voltage is determined by what the power pot is set to. But as you bulb ages it does get hotter and less efficient etc. The 500w bulbs do run slightly hotter.


You're projector should ALWAYS have adequate airflow. If you never experienced a shutdown from overheating the thermal protection circut I am questioning JVCs response to heat damage diagnosis. Like in...heat damage to what?


I suspect they saw the non OEM bulb in there at the repair place and told you that to cover their stuff etc.


Had you replaced it back to the OEM bulb would they have given you a different diagnosis?
 

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Discussion Starter · #7 ·
Tryg:


There is apparent heat damage on the outside of the case at the discharge point. When I say apparent, the outside of the case around the discharge case is slightly discolored, a sort of light brown around the vents. I can't say for sure, but I don't remember this prior to the last bulb replacement. Once the bulb was replaced we reinserted it into the Whisper Flow hush box.


Also the engineer I spoke with at JVC (Pinebrook, NJ) said the large capacitor on the igniter board showed a raised head (or top) which from experience they've determined as heat damage related.


The bulb we obtained from Ralph Fenton ( Ralph I hope I have your name right) looks very very similar to the one I took out. Maybe it is a different OEM or a different series, but very similar looking.


I raised this question because I know several other folks on the forum have done similar things: A: Put foam inside of a hush box and B: Used after market bulbs for replacement.


So i am not sure what happened, but am hopeful we will get some additional input to help us get to the bottom of this.


Thanks for the input.


Chuck
 

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Chuck, just out of curiosity, did you get any feel for whether or not JVC frowns on these replacement bulbs? And/Or whether or not the use of one would void any warranty you might have left?


Thanks,


Andy K.
 

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Chuck,

I've been inside that repair facility [it's about a stone's throw away] and met some the engineers and techs. They seem like real good folks- hope they take care of you OK.

-Dave
 

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Discussion Starter · #10 ·
Andy:


I spoke with John Meenan (sp) and he was professional.


To test the unit I put an older JVC supplied bulb into the unit. When this did not fix the problem I sent it back to them with the old JVC bulb installed. So it is a JVC bulb.


I was under the impression that the bulb we have from Ralph Fenton is supplied by Perkin-Elmer to JVC and is the same actual bulb as the one used on the G15. Since our unit is a G11 that explains the bulb differences (420watts on the G11) and 500 watts on the G15. At least as I understand it.


Our unit is out of warranty anyway so that is not an issue with us.


If your unit is under warranty and you wanted to try this, I think I'd be sure it was in an extremely well ventilated area. On second thought I'd wait until my current bulb wore out as well as my warranty.


Even with this hassle I am still happy with this unit, even considering the heat and noise issue. I've yet to see a newer digital that looks better. Admittedly I have not seen all of the newer units.


Chuck
 

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Tryg wrote:
Quote:
The 500w bulbs do run slightly hotter.
I've heard contradictory info on this subject. I have read messages from people who say that replacing a 420W xenon bulb with a 500W bulb actually makes it run with less light output and less heat.


If any of you know about flashlight bulbs, try putting a 12V bulb in a 6V device, and you will notice that it runs very dimly, and doesn't produce as much heat as a 6V bulb would. But put that same 12V bulb in a 12V device, and it burns nice and bright. I think something similar might be the case with the xenon bulbs; if (just for the sake of discussion) the 420W bulb is normally supplied with a 420 Volt input, and the 500W bulb is normally supplied with a 500 Volt input, then you would expect the 500W bulb to burn dimmer and with less heat when it was driven at 80 Volts less than normal (420V).


I think the above is an oversimplification, as the power supplies are not constant-voltage, but my point is simply "lets not jump to conclusions".


The new bulbs may actually be running cooler.


I personally would suspect the hushbox. Unlike most homebrew D-ILA hushboxes, the whisperflow does not physically seperate the intake from the air outlet. So some of the air that goes in the projector comes from the hot air that just came out of it.


You might want to try measuring the temperature at the air intake and outlets on the projector, both in free air and in your hushbox. When I did that with my hushbox, I found that the temperature at the intake was about 95 degrees after a few hours of use, and the temperatures at the exhaust ports were 130-135 (small outlet) and 180-190 (large outlet).


I'm almost certain that the whisperflow would yield a higher intake temperature, but it would be interesting to see how the exhaust temperature compared; it could be lower or higher and that is probably the critical measurement.


I think my hushbox is adequate but perhaps not ideal in terms of thermal performance. Here's info about it:

http://www.tommorrow.info/ht/dila_hushbox.html


-Tom
 

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I have a Radio Shack tempeture probe that fits nicely in between the slots on the exhaust grill. My temps run about 150 F. It tops out at 155 F, but at times it's gone well over (judging by the amount of time it took to return to 155 after the PJ was off).
 

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I assume you are measuring on the large exhaust grill. You might try measuring on the smaller one, which shouldn't get above 150. I ended up buying Polder brand cooking thermometers because they go up to hundreds of degrees.


-Tom
 

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Discussion Starter · #14 ·
FWIW, have received some interesting messages indicating that some people question the entire idea about the bulb being the source of the failure.


Also someone told me that has been a rash of capacitors that were marginal that made their way into a bunch of products. Something also to take notice of.


I plan to operate the unit in a open space for a while when I get it back and see what happens.


Chuck
 

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Thanks for the feedback, Chuck. I plan on replacing my current bulb with an genuine JVC one which should take me through the remainder of my warranty.


How much did the repairs come to? I have visions of multi-thousand dollar part costs. (Did you know that the part cost to replace 1 DILA panel is apparently $6500!)


Andy K.
 

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Chuck,


Yes I initially assumed you were suggesting it was related to the bulb. I highly doubt it is/was.


Any component can fail causing a varety of issues. I hope you get it resolved without to much $$$


but it does however sound like better airflow would help you
 

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A properly designed hush box, which does not allow recirculation of the exhaust air into the intake, should LOWER the temperature of the projector, not raise it.


I've done quite a few lamp replacements, some with JVC lamps and some with Atlas. As near as I can tell from the measurements, there isn't any difference - I see temperature variations with both. The biggest difference may be how well the heat transfer compound was applied.


fyi - if one of the ILA panels is bad, JVC replaces the entire optical block, not a single panel, that's what costs $6500.


William
 

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Hi Chuck,


Many people with the WhisperFlow Projector II design did separate the hushbox into two chambers with foam. Hence, with this modification, found that the flow of air occurred even with the hushbox fans turned off. But, you will need to add your spare fan to create two chambers with the old WhisperFlow I design. Please do a search on this forum for details or e-mail me. Also, I still think 2" of foam added of the discharge side could be causing some backdraft into the projector. But, with the two chamber design, this may not be an issue.


All the best!


Dave
 

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Discussion Starter · #19 ·
Andy:


JVC initially quoted about $1700. Half of that was to replace the cover (plastic ) and the three operating labels. When I complained they removed the cover replacement and label replacement and the cost is now $800.


I spoke with the engineer I've been talking with and stated that we think the pricing by JVC is brain dead. Sorry, there is just not a better way to say it.


They have arguably one of the better, if not the best, overall digital technologies on the market. Yet, they seem to have some trouble selling it and supporting it.


We owned an NEC LCD projector for four years prior to the JVC. It never missed a beat, lamps lasted for 2000 hours, was easy to use , lamps were reasonable etc. Admittedly the picture was no where near as good as the DILA. But, with things changing every day . . .


When a customer has a failure, if you try to charge $800 to replace the plastic case and three labels, most customers will never have faith in your pricing again.


I have not yet heard back from them, so we will see what the final Talley is.


I really liked the projector up to this point. I am disappointed with the pricing strategy by JVC and it will make me take this into account the next time we get some AV gear.


William:


If my panel fails and they want $6500 to repair it they can forget ever have any business from me or anyone I speak with ever again. While far from being an expert I have still helped numerous friends put together systems over the last few years.


I think this performance by JVC is shameful.


While the engineer I've dealt with has been professional and helpful, when I pointed out the absurdity of what they were charging to replace the case, he then explained the work to replace the igniter board and two fans was detailed etc. The problem with this is, that even if true, now I wonder.


It is not good when a company tried to charge $800 for replace two pieces of molded plastic and three stick on labels. I'm in the computer biz and know what the source cost for a lot of these types things are.


They wanted $21, $24 and $54 for the stick on labels and $500 (rounded) for the two plastic molded parts plus three hours labor (@ $125 per hr) to put this stuff on????




Chuck
 

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While I certainly wouldn't say those are low prices, I do have sympathy with JVC. It's all about economies of scale; if there were zillions of D-ILA projectors out there that needed support, then they could achieve some economies of scale in replacement parts, but as it is the cost of stocking replacement parts probably does require very high prices. For every plastic part that they sell for $500, they probably have to stock and never sell ten or twenty other equivalently valued parts. It may be that the part is really only worth $50 to build, but if they have to stock ten times as many parts as actually get sold, $50x10= $500 and they have to recoup that cost. Not to mention the time value of the money they had to spend on that part 5 years ago or so when the assembly line was operating, and the overhead of storing things for many years.


The same thing is true with automobile parts, where buying all the parts to make a $15k car would cost you $100k or so. Commonly replaced auto parts however are much more competitive because the market is big enough that they can achieve economies of scale, just like xenon lamps are relatively competitive (more like twice production cost than 10x production cost).


Just having someone around who can diagnose and fix problems with the projector is really valuable, even if they are charging $125 an hour (which incidentally isn't that much more than a car mechanic charges).


I'm not trying to say that these are great prices, but just that I doubt they are making much of a profit off this kind of service, and it is in our interests as D-ILA owners to have them around because it is better when we can get our projectors fixed for $800 rather than having to spend thousands of dollars on a new one. In my mind there is nothing that JVC can do to make their service cheaper except ramp up the volume of projectors produced and sold, which they seem to be trying to do with their newer more competitive projectors. Of course if only they would really "get home theater" perhaps they could finally break through but that's another discussion.


-Tom
 
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