Axiom Home Page Forums General Discussion Advice from Axiom Owners DLP getting dim?

I didn't want to intrude on Cam's calibration thread, but do DLP bulbs get dimmer as they age, or do they maintain relatively even brightness until failure?

Seems like I can't watch a "dark" scene during daylight anymore. It's OK at night, but you just can't follow a dark scene unless the room is really dark lately.

The room lighting hasn't changed....

I'd say they probably do, especially if it is a halogen cycle bulb. The halogen cycle is supposed to allow parts of the filament to atomize and move about the bulb and then be re-absorbed (very simplified explanation). But over time some of these particles build up on the inside glass and not as much light can pass through.

It may seem counter-intuitive, but running halogens below their proper operating temperature shortens their life, because they can not properly "cycle". So some of those bulb-saver settings aren't.

I've read from a couple of different sources that say yes the DLP bulbs do get dim with age, seems like the AV shop where we bought ours told me that the picture will be late turning on whenever the bulb is nearing the end of it's useful life and I've also read on another forum that a forum member had his bulb pop and explode which made for a mess with the glass pieces scattered over the inside of the TV ... a situation I surly don't want to get into.

Our DLP has been getting dimmer and dimmer over the past couple of months and I'll be replacing the bulb straight from Mitsubishi probably in the next, well I guess few minutes while it's on my mind. Our TV is supposed to have a time to replace bulb display whenever it is time but I'm thinking the fellas from Mitsubishi may have forgot to program that into our set, it's only been four years on a bulb that most say should be replaced every 2.5 to 3 years. Wonder if some dude driving around in a Galant is curious to know why a 'Time to replace TV bulb' light keeps coming on the instrument panel of his car now.

Thanks for the reminder Mark!


Oh yea, anybody have an idea how to reset the 'Change Oil' display light on a Mitsubishi WD-73727?

Rick,
Have you checked how many hours your Mits. has on it? I have a WD-73734 but I believe this code may fit many models.
Press the menu button, then pres the numbers 2 4 7 0
The hours on your TV will show in the bottom left of screen (if it's like mine). This is not resetable. It is hours on the TV, not the current bulb. If you want to keep track of bulb #2's life, just log the hours into you manual or wherever.

I had 1,052 at the end of year one a few months ago. It was fun to find out the DLP had an odometer! From what I have read, I'm expecting 4 BILLION hours from my bulb! (ok, maybe that's thousand )YMMV

Dave whenever I did that it has a set of five numbers on the bottom of the screen, the first two are 04392 and 04390, the other three numbers are 00001, 00001 and 00001 ... I assume the 04392 is the hours on the set?

Seems like a lot to me.

You have to stop getting drunk and falling asleep with the TV on....

Whoa, you know me too well Mark.

Yes, I would say 4,392 could very well be right. Easy to check though. Check it, write it down, and recheck the next day, week, or end of TV watching night, whatever, to see the change. Then you will know for sure.


If you have four years on it, you (1,098/yr) are right about at the same burn rate as me at 1,052 in year one. I have heard bulb life quotes like you mentioned at 3 yrs or so. Huge variations by # of hours watched and if you have unknowingly left the bulb brightness set at the brightest setting set at the factory. First thing to do is turn bulb brightness down. (to 'Natural' on Mitsub. which approximates 6500 kelvin. Not 'brilliant' or 'bright')

From what I read bulb hour quotes ranged from 3,000 In 'torch mode' (brightest setting) to 4,000 6,000 7,000 bulb hours. The amount of on/offs affects the bulb life too. One guy who had a Misub. DLP in a some kind of a hospital ward room or something similar said that TV was literally on 24/7 for a full year. He said MAYBE it had been turned off once or twice in the whole year. I don't recall if the bulb was still going (I think so), or if that is when he replaced the bulb. But after just over a year the TV had 10,000 hours on it. I do not think he was BS'ing. So with normal on/offing I am guessing 4,000 hrs conservatively for me.

Yes, when a DLP nears the end of its life, the pictures dims. First slowly - almost imperceptible. You mess with the brightness and contrast, and then it start really falling off fast. You can't even keep up, until one day it goes POP. Mine made a mess as it shattered the glass. But replacement is easy, and it works fine with the new bulb. I only got 2000 hours out of my Sammy, so if your got 4000 I feel better. Honestly, that has delayed my projector purchase as I a think the tech needs to mature a bit. Now they are using LEDs and lasers which don't die.

I think either my dog or cat turns the TV on during the middle of the night. Not only because of the hours on the TV, but also because we keep getting these shipments of 'new and improved' pet toys and treats! I will need to cut up their credit cards. They just cannot understand money...

To the best of my knowledge, Marcus, DLP bulbs do get dimmer as the approach the end. Mine is certainly getting dimmer and it's going on 3 years of usage. Don't really know the hours. I have a new bulb ready and waiting but I don't want to install it prematurely because I will likely have the TV re-calibrated professionally when I do replace it.

Wow, I'm glad to hear the dimming wasn't just me.

There. Run with it.

A new bulb installation would necessitate readjustment?

Dave. My understanding is that these are all HID (high intensity discharge) lamps of some sort and they are either on or off. Dimming just controls an iris. Bulb life on these lamps seems to vary a lot and can be as little as 2K hours and as much as 10K hours with the normal range being 4-6K.

I think I'll order a bulb.

I don't see myself getting anything new for another year or two, as my next one wil have to have real blacks and that's pretty pricey. It's unlikely this bulb will last that long and since I bought this in the Fall of 2004, I'm not surprised at all that the bulb might be failing...

Thanks guys!

I don't know if "necessitate" is the right word, but I know that a professional calibrator wants the bulb to have at least 100 hours on the bulb before he does a calibration and they recommend having the TV calibrated once a year. Yes, I know there is a financial incentive for such a recommendation. However, most calibrators offer recalibrations of the same TV at a substantial discount ($400 for the first; $250 for subsequent calibrations)

I last had my TV calibrated 3 years ago, so I think having it recalibrated again would be prudent. However, I don't want to have it calibrated with an older, dimming bulb so I'll wait until I put in the new one before recalibrating.

Instead of replacing a dimming bulb, why not just invest in night vision goggles?

OK, that's silly but admit it, you can't tell me you don't want an exuse to go buy night vision goggles.

OH! MY! GOD!

THAT.......WOULD....BE......SO......COOL!

But, er, uhm, wouldn't everything have a greenish cast? What would the calibrators do?

By the way, I'm into my 6th year of my Sammy DLP bulb, which surprises me. I checked the specs and my Samsung manual says it could last up to 8000 hours. Mine is the generation that had the HDMI input and a DVI input (2003).

Cheers,
Alan

Well whadaya spects when you watch TV only once a month. Sheesh!

Mine is also (1) HDMI and (1) DVI.... I bought it in the Fall of 2004 (because that's when I joined here and know it's when I was setting up my HT).

I'm surprised it's lasted this long, but then again, it gets 2-4 hours a day at most.

Yes, that's about the same frequency of TV watching for me, maybe less. I was wrong on my date--I just checked and it was summer of 2004 that I got mine.

Alan