| Author |
Message |
Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
|
| Posted: Thu Oct 29, 2009 6:20 pm Post subject: Digital projector lamp question |
|
|
OK guys, I have a DWIN TV4 DLP projector in for service. The ballast was shorted, one MOSFET was blown, which fried some stuff on the SMT driver PC board.
Amazingly enough, I found a ballast in China for a reasonable price, and it came in this morning. Despite the fact that it looked like DWIN had their lamp connector custom made by Osram, the ballast manufacturer, I managed to use some heat shrink tubing and some HV sleeving to mate the two, it's a solid connection.
I powered the projector up, and lo and behold, the lamp how fires up.
BUT...
The brightness of the screen flickers, at one point went deep blue, then back over to normal bright/dim, maybe a flicker every second or so, then eventually the bulb goes out and the image disappears. THe LED on the top of the DWIN flickers rapidly, indicating an error condition I'm assuming.
<update> the bulb has 1100 hours on it according to the menu. I think this unit has a 2000 hour bulb life.
I have zero experience with DLP bulbs, so I don't want to tell the customer to change the bulb if there's still an issue in the set.
Thanks!
|
|
| Back to top |
|
 |
macgyver655
Joined: 22 Aug 2007
Posts: 8508
|
| Posted: Fri Oct 30, 2009 2:38 am Post subject: Re: Digital projector lamp question |
|
|
| Curt Palme wrote: | OK guys, I have a DWIN TV4 DLP projector in for service. The ballast was shorted, one MOSFET was blown, which fried some stuff on the SMT driver PC board.
Amazingly enough, I found a ballast in China for a reasonable price, and it came in this morning. Despite the fact that it looked like DWIN had their lamp connector custom made by Osram, the ballast manufacturer, I managed to use some heat shrink tubing and some HV sleeving to mate the two, it's a solid connection.
I powered the projector up, and lo and behold, the lamp how fires up.
BUT...
The brightness of the screen flickers, at one point went deep blue, then back over to normal bright/dim, maybe a flicker every second or so, then eventually the bulb goes out and the image disappears. THe LED on the top of the DWIN flickers rapidly, indicating an error condition I'm assuming.
<update> the bulb has 1100 hours on it according to the menu. I think this unit has a 2000 hour bulb life.
I have zero experience with DLP bulbs, so I don't want to tell the customer to change the bulb if there's still an issue in the set.
Thanks! |
Is there a question in there? 
There is really no way to test the bulb. Its pretty much just change it and try. If you do this stuff daily then the bulb purchase is not so bad because if it still doesn't work you can save it for the next project.
The only thing I can tell you is usually when the ballast is bad, so is the bulb. But thats not 100%.
Maybe check power supply caps, but I'm thinking you already did.
My suggestion is maybe if you get enough of these you can use them for ramps to drive your car up on to change to oil.
Or you can use the BAT fix....... Batter up!
|
|
| Back to top |
|
|
macgyver655
Joined: 22 Aug 2007
Posts: 8508
|
| Posted: Fri Oct 30, 2009 8:57 pm Post subject: |
|
|
|
Have you priced a lamp yet?
|
|
| Back to top |
|
|
Curt Palme
CRT Tech
Joined: 08 Mar 2006
Posts: 24396
Location: Langley, BC
TV/Projector: All of them!
|
| Posted: Fri Oct 30, 2009 9:05 pm Post subject: |
|
|
|
$220 on eBay. I'm waiting for another TV4 to come in on Monday so I can swap bulbs. Neither the customer nor I want to spend the $$ on the bulb if that's not it.
|
|
| Back to top |
|
|
macgyver655
Joined: 22 Aug 2007
Posts: 8508
|
| Posted: Fri Oct 30, 2009 10:00 pm Post subject: |
|
|
|
I located a new OEM Dwin replacement for 189.00 with 50.00 off a second one, if you need.
|
|
| Back to top |
|
|
macgyver655
Joined: 22 Aug 2007
Posts: 8508
|
| Posted: Fri Oct 30, 2009 10:04 pm Post subject: |
|
|
Oh, and it has a 1 year warranty vs 90 days on the ebay bulb..... 
|
|
| Back to top |
|
|
ruby123
Joined: 13 Nov 2009
Posts: 2
|
| Posted: Sun Nov 15, 2009 7:59 am Post subject: |
|
|
|
Hi, this is my first posts here In curtpalme , Well i have heard pretty bad reviews for chinese PJ. Well changing the lamp is pretty good idea. Recently i had also change my lamp and it was not that bad i got my lamp for USD185 + 15 shipping from http://www.projectorlampsworld.com/ they have almost all the lamp in between 150-250. you can check yours as well they are pretty reliable company when it comes to product. Much better than ebay guys.
|
|
| Back to top |
|
|
cmjohnson
Joined: 03 Apr 2006
Posts: 5180
Location: Buried under G90s
|
| Posted: Sat Jan 02, 2010 4:12 pm Post subject: |
|
|
I think that if you were to monitor both voltage and current in-line with that lamp, and put a current probe in the circuit and monitor it
with your trusty oscilloscope, you would find that the output from that Chinese ballast is noisy as hell and not at all stable with time.
Make a similar test on a Barco supply and you'll see a world of differerence in stability and noise levels.
The lamp's performance can never be better than the ballast running it.
But as a reminder, if making this test, take into consideration the fact that the lamp strike pulse runs into thousands of volts,
and running current levels are often in the tens of amps. You'll need robust measuring equipment for it to survive actual
running loads.
You can get some usable data just by running a current probe around the lamp wires. You'll be able to scope out any noise and
instability but you won't see actual current levels.
CJ
|
|
| Back to top |
|
|
macgyver655
Joined: 22 Aug 2007
Posts: 8508
|
| Posted: Sat Jan 02, 2010 4:55 pm Post subject: |
|
|
|
To all non techs. Please disregard the above post. And CJ, you should know better then to post something like this. This can be dangerous to both equipment and especially YOUR LIFE. These are dangerous voltages. And if a tech was reading this thread, he already knows how to test out a ballast so this info is just dangerous to a non tech.
|
|
| Back to top |
|
|
cmjohnson
Joined: 03 Apr 2006
Posts: 5180
Location: Buried under G90s
|
| Posted: Sat Jan 02, 2010 6:27 pm Post subject: |
|
|
Curt is qualified to do this. Anyone who's working on a digital projector around the lamp circuit should be aware of the voltages and
currents involved. What I posted is for the benefit of those of us who KNOW WHAT WE ARE DOING. I'm not going to dumb down
my posts for the benefit of the non-technical types. They should know what to stay out of, and it has high voltage warnings all over it.
Darwin lives inside the ballast. Don't provoke him.
CJ
|
|
| Back to top |
|
|
macgyver655
Joined: 22 Aug 2007
Posts: 8508
|
| Posted: Sat Jan 02, 2010 6:49 pm Post subject: |
|
|
| cmjohnson wrote: | Curt is qualified to do this. Anyone who's working on a digital projector around the lamp circuit should be aware of the voltages and
currents involved. What I posted is for the benefit of those of us who KNOW WHAT WE ARE DOING. I'm not going to dumb down
my posts for the benefit of the non-technical types. They should know what to stay out of, and it has high voltage warnings all over it.
Darwin lives inside the ballast. Don't provoke him.
CJ |
Then if your high voltage test post was directed at Curt then why not PM it to him like I PM him tons of info that should not be posted to non techs.
This is like posting on how to test the high voltage in a projector and someone attempts it without knowing of the dangers involved. And those stickers fall off or are not always in plain view.
I'm not trying to start something here with you but I'm not thrilled at posting life threatening tests.
|
|
| Back to top |
|
|
bbfarmht
Joined: 27 May 2006
Posts: 1273
Location: Where the Mississippi runs east to west!!
|
| Posted: Sat Jan 02, 2010 7:40 pm Post subject: |
|
|
| macgyver655 wrote: | | cmjohnson wrote: | Darwin lives inside the ballast. Don't provoke him.
CJ |
Then if your high voltage test post was directed at Curt then why not PM it to him like I PM him tons of info that should not be posted to non techs.
This is like posting on how to test the high voltage in a projector and someone attempts it without knowing of the dangers involved. And those stickers fall off or are not always in plain view.
I'm not trying to start something here with you but I'm not thrilled at posting life threatening tests. |
Try and tell my tools that, I have shorted a few out in my first year of teching on electric fork trucks. Those caps hold a tremendous charge, and when your changing contacts out sometime you can't avoid being too close to them. However if you get your self some heatshrink and put it on your extensions you will avoid shorting the caps out(till you wear the heat shrink off and have to replace it cause you thought you could use that extension a few more times that way.  )
_________________
Adam
"Any society that would give up a little liberty to gain a little security will deserve neither and lose both"
Benjamin Franklin
|
|
| Back to top |
|
|
cmjohnson
Joined: 03 Apr 2006
Posts: 5180
Location: Buried under G90s
|
| Posted: Sat Jan 02, 2010 8:58 pm Post subject: |
|
|
I would like to think that in this forum at least, the average forum member is a little bit less likely to attempt stupid electrical tricks
than the general populace at large. I wouldn't call ANYONE I've seen post here, a dummy. They all seem to have some common sense
and I'd trust them to not attempt what they're not qualified to do.
Maybe you're a bit more pessimistic about them than I am. I prefer to think that people are smarter than you give them credit for.
CJ
|
|
| Back to top |
|
|
macgyver655
Joined: 22 Aug 2007
Posts: 8508
|
| Posted: Sat Jan 02, 2010 9:17 pm Post subject: |
|
|
 I'm in a good mood today so I'll leave it at that and wont respond........
Well maybe one thing. When you post something on this forum its is not just available to those who would post here. Google will bring in those from all walks of life and a desire to save money and try a repair themselves without any knowledge, and it is becoming more widespread then not. Your posting to the internet, not just Curtpalme.
Ask Curt how many self repairers boards he has received butchered. I could give you my number but you wouldn't believe me. And my tech contacts could confirm thousands more.
And lets leave smarts out of the equation......
|
|
| Back to top |
|
|
|
|
