|Originally posted by amk1173
My 50" GWIII Started Buzzing continuosly on startup about 2 weeks into its Life. After about 1 1/2 weeks the Unit failed to turn on regardless of the number of attemtpts. After it would not turn I opened the Lamp cover to check the bulb and found the bulb had disintegrated inside of it's housing.
This seems to me to be a defect in the lamps and not in the GWIII. The Buzzing is merely a byproduct of the Unit attempting to start the Bulb as well said in irgaac's Great post.
Also Welcome Back umr, Glad to see your back on.
Thanks for the compliment :)
Can you describe what you mean when you say the lamp disintegrated in the housing? These lamps have very high pressure gasses in the and I am curious if the lamp envelope failed (which should have made a very interesting noise) or if you just didn't see normal lamp guts inside the bulb and assumed they had disintegrated.
|Originally posted by mobocracy
After reading all these messages, I'm coming to the following conclusion:
1) A brief startup buzz is a normal side effect of the voltages necessary to kick-start the lamp. The glowing component is also a normal part of this circuity.
2) Many early lamp failures can be fixed by reseating the lamp. These premature lamp failures are accompanied by multiple buzzing due to bad connectivity between the bulb assembly and the socket resulting in multiple startup attempts.
Mine quit after 3 days with buzzing and the "Lamp" light going red. I reseated the bulb (which didn't appear loose, or even badly seatable due to the design), and it worked again right away and has worked since. I still get a very brief buzz on power on, but that's it.
A brief buzz doesn't bother me, but I still want to talk to a technician about this. If some sets have NEVER buzzed at all, I'm kind of concerned.
You have pretty much hit the nail on the head. With the recent reports of reseating the lamp being a possible cure I am curious to know what the "failed" lamps look like. A poor mechanical connection would exhibit the same symptoms as a faulty lamp or ignitor assembly.
If some of you who have a spare (old) lamp would be kind enough to look at them and post back answers to the following questions we may be able to diagnos this issue a little further.
Is the glass part of the lamp anything but absolutely clear?
Are the contacts on the bottom of the lamp where it fits into the housing showing any discoloration or pitting?
|Originally posted by TV21CHIEF
I've had my '50WE610 for about a month. It's on for maybe 4 hours a day. I've had the previously mentioned buzz at startup since day one and ignored it assuming it had something to do with lighting the lamp. Being in TV I've also had a lot of dealings with arc and HMI lights. Anyway after being out of town for 3 days over Thanksgiving it won't turn on and the buzz happens briefly then the LAMP light blinks. I reseated the lamp a couple times. The lamp looks brand new.
I started off my stint in the business working for LTM. Check the lamp socket connectors and see if there is any oxidation or discoloration.
|Originally posted by dr_mark2001
It seems to me that the lamp and its circuitry is not robustly designed, if one double hit on the power button during the first few days of operation could cause lamp failure.
I'll be sure to be careful with my power button on the GWIII as I have been to date.
irgaac - thanks for the technical information, would you or anyone know the expected life of the GWIII bulb (50", 100 watt)? I have yet to receive a definitive answer on this.
The lamp and it's housing including the ignitor and ballast circuit are designed as a package by Philips from what little documentation I have been able to find. Philips states on their UHP site that the 100w lamp has a life of ~15000 hours. Design and operating constraints will lower that value. This is the same lamp that is used in the Smasung DLP units from what I can tell so the 8000 hour number they quote should be accurate for the Sony sets as well as long as Sony engineered enough ventilation in the set.
I doubt these problems are being caused by a few mistrikes or short run times, although both of those conditions will shorten the total hour life of the lamp. More than likely the bulbs are not seated correctly because of shocks during shipping and after a couple of thermal expansion cycles they just lose good contact. It could be something as simple as oxidation on the contacts of the bulb or the socket and the settling of the blub after a few thermal cycles may move the oxidation into the contact area. Removing and reseating the bulb in most cases would remove oxidation from either of the contact points. The worst case scenario is that the high voltage needed to start these lamps may find another path to ground when the lamp has poor contact which woiuld make this a recurring problem as the new lamps become harder to strike and would require replacement of the lamp socket assembly.
Wow that was long, sorry didn't mean to ramble for so long. :D