ROP bulb failure (Updated 01-25-2008)

[WildChild]

I found today that my ROP-HI bulb stopped working. There is no sign of filament breakage, no sign of leak, no explosion, no nothing... What can cause a failure? It just doesn't light up anymore and doesn't show continuity with my DMM anymore. Any way to solve this?

 

[Icebreak]

Re: ROP bulb failure

I'm guessing this isn't the one that had its anode solder blob melt. Weird. Long shot guess here, do you think it might be possible that one of the pins inside the PR base came loose? Maybe due to heat?

 

[WildChild]

Re: ROP bulb failure

I'm guessing this isn't the one that had its anode solder blob melt. Weird. Long shot guess here, do you think it might be possible that one of the pins inside the PR base came loose? Maybe due to heat?

I have another information. I have just been told that the light took a drop while my gf was cleaning the desk. It was obviously turned off when it took the drop. Yes, this is the bulb that had its solder blob reformed after it melted. So a a pin came loose? There's a hole filled with solder on the side with a pin appearing on the center of it. I melted again the solder in this hole and the positive solder blob with no positive effect. Anyway! I have a spare ROP-LO bulb and I'm waiting for 3 spare packs of bulbs.

 

[Icebreak]

Re: ROP bulb failure

Maybe so. It might be possible that when the PR base over heated when the solder blob melted that the soldered attachment point for the pin on the side of the PR base was compromised. Then, when it recieved a shock it could normally take, it broke loose.

Well darn. I was hoping your fix would last longer. I remember it quit smoking after you reformed the blob. Can I ask about how much longer it ran after the fix? I'm especially interested because it may be that you've correctly identified a failure mode and also found the solution.

Thanks.

 

[WildChild]

Re: ROP bulb failure

It has not lasted 2 battery charge. I haven't used it much since I reformed the solder blob. When it smoked, it was when it was new, in the first 5 minutes. I noticed the solder blob melted only 5 days later. I decided to add those pictures to show how the plastic bulb holder melted:

 

[Icebreak]

Re: ROP bulb failure

Wow. It did get hot.

Thanks, Wildchild.

 

[WildChild]

Re: ROP bulb failure (New data available 01-25-2008)

New data available! I received 3 packs of new Pelican bulbs. I put back my current ROP-LO bulb in the tailcap as a spare bulb and I tested a new HI bulb. First, I let it run for 5 minutes with the head off inside a glass in case the bulb would explode. After the run, the glass was fogged up (like the fog that appeared on the reflector the first time). I let it cool down and I removed the bulb. IT'S HALF STUCK! The solder blob melted and it was slightly stuck on the positive contact of the bulb holder. There was also a strong smell of glue or flux in the room! I reformed the solder blob, let it ran again for 5 minutes, let it cool down, removed it... No melting! There IS a quality problem with the solder blob on the ROP-HI bulbs! Oh, I forgot, the solder blob was gray and dull before it melted. It is now shiny since I reformed it. I checked my other spare bulbs. All ROP-LO solder blobs are shiny, all ROP-HI solder blobs are gray and dull. Next time my ROP-HI bulb fail, I'll try to reform the solder blob with an iron before using it to see if problem happens. Here are 3 pictures I took:

See the fog on the right side of the glass:

Melted solder blob:

New bulbs, LO bulb on left and HI bulb on right: