Mercury arc lamp exploded...

Hey guys,

Well, this isn't strictly HID [Mods, move if you like!], but it does deal with an HID bulb, so let's start here first.

I have a Toshiba 62HM195 rear-projection DLP. The light source is a 150w lamp that appear(ed) to be a mercury arc lamp. It is housed within its own reflector assembly. It appeared to be a vertical-electrode lamp, like the WA Solarcs or any other HID I've ever seen.

Last night, while I was playing some XBox 360, there was an extremely loud "POP" and the screen went dark with the TV's lights flashing. I powered everything down and hauled out the lamp assembly to find - to my surprise - the entire bulb had exploded. There is a glass window in front of the reflector, so nothing ricocheted around in my TV, but the whole thing is filled with quartz sand, with blackened bits on one side of some fragments. The wire support and quartz housing for the upper electrode is still intact, but the base is completely gone, with shattered bits of plastic or ceramic inside the reflector.

The TV is used maybe 12 hours a week and I've had it since May 2006.

O Almighty Ra, knower of all things gas-discharge [and anyone else, too!], is this the usual failure mode for these lamps? I was expecting a long fizzle toward electrode death, not catastrophic sudden failure.

I have another lamp on the way and I should be able to get a replacement out of Toshiba for a warranty event, but this is just bizzare to me! I'm not going "ZOMG DANGER" here, because nothing was hurt and I'm not worried about injury, but it was surprising, and I'm curious.

Hi Sable,

No, this is not "usual failure mode" but its not impossible !

These lamps operate under extreme high internal pressure !
They must be operated within certain temerature conditions, any change can cause them to burst!

There also is the possibillity that a minor problem occured during the production of the quartz-bulb.

Sorry to hear your bulb is history, I hope there is no damage to the light-enging as a cause of this. I hope you can get a new one cheap, they are quite expensive!

EDIT: Oh, I forgot: You should check the air-inlet-filters (and outlet-filters) as well, klogged filters also can cause premature lamp-failure !


Regards,

Ra.

interesting...i should clean my bro in law's tv then

Hi Ra!

Thanks for responding so quick! I've recently discovered that there was a manufacturing problem with some of the first-run bulbs for my TV, so I'm a little less surprised by the failure. The bulb and housing are completely self-contained, so there *shouldn't* have been any damage to the light engine - I'll know next week when the bulb gets in (US260.00 shipped - owch!).

Man, CPF is really a great resource...

Not a bad idea!! scaredofthedark,,

Certainly in a dusty environment, filters get klogged real quick. Quality brands have temperature-sensors that should warn you, or shut things down before things get into the dangerzone. But I shoudn't wait for that to happen.

I own a high-def projector, and I clean the filters every 3 months or so.

Filters usually are user-cleanable or replaceble.


Regards,

Ra.

If their was a bulb defect, call toshiba and tell them to either send you $260 to pay for a new bulb, or have them send you a free one. They are to expensive to not be replaced by toshiba when they fail catostrophically, and prematurely.

Ra said:

Hi Sable, EDIT: Oh, I forgot: You should check the air-inlet-filters (and outlet-filters) as well, klogged filters also can cause premature lamp-failure !

Click to expand...

Cooling air flow is quite critical to bulb life in these higher wattage applications. Filter mainenance is a key to this.

65535: Toshiba warranties all of their lamps for one year, and I've only had my set for eight months - I'll get a new bulb out of them for bupkis. The problem is that it'll take a couple weeks to get here.

I was going to buy another bulb anyway, so I'm not actually out anything - just plans had to be sped up a little. This way, I'll have a spare bulb after everything comes in.

Anyone want pictures of the exploded lamp? It's kind of spectacular.

post them!!!
i wonder what it looks like

Yep,, cool,,

Pictures of exploded things always are interesting:

I have a picture of an exploded-view of my mini-HID...


Take a closeup of each fragment !!! :lolsign: :lolsign:


sorry,, coudn't resist.. CPF should also be fun, don't you think ??

Regards,

Ra.

This is the reason why some lamp specs to be never be operated outside of a proper enclosure.