Thoughts on a couple of lights...still too much of a n00b to actually "review"

Decided to stop just reading and startin on what will prolly be a new obsession for me.

On April 28th I broke down and ordered an UltraFire WF-502B from DX (yeah, I know better now...). Showed up about 3 weeks later (pretty quick for them), but was crap. Just generally flaking out on me. Went back and forth with the CS dept and finally returned it for a replacement. That finally showed up on June 29th. Still crap though. Got back in touch with CS and they offered to give me half credit and I'd just keep it to try and fix it. Sure....was gonna be messing with it anyway.

Used that credit (as well as some others that they owed me) to grab an UltraFire KH-T60 HA-II XM-LT60 on July 4th. That showed up on July 25th. LOVE this light!! Far from an expert here, but can tell that there is no way that it's truly 1200 lumens, but is still REALLY friggin bright! Only complaint is that the fit between the reflector/lens/crown is a bit sloppy. (well, that and the useless strobe modes, but at least the memory works on this one) Doesn't rattle, but can tell that it's not nearly as snug as it should be. Trying to hunt down some o-rings to add and seal that up....will post that in another thread.

OK, back to my 502B. Just got a Cree T6 3-Mode Drop-in for it and while much better....it still is flaky as all hell. Guess it's time to start my tinkering on it.

Does your 502b have a separator (ie wall w/ a metal button) between the battery compartment and the drop-in compartment, or is it straight-through (like most p60 hosts)?

just by pass the switch and see if its "flaky" , i assume its kinda getting brighter and softer ....?

if its not the switch the test the led to be safe and repalce the driver

also make sure its not shorting on the reflector , just remove the reflector and see if its flaky

and check the solder job make sure the positive is not blobed over the edge

There’s no separator on the tube. I’m fairly certain at this that it’s the switch since it’s still “flaky” with the new drop in.
And by"flaky", just a general bad connection reaction.random dimming, turning off, etc. Tapping the side usually brings it back. I did initially test the switch with a meter but seemed fine, but not being under load could just be fine. I’ll probably rip it apart again sometime this weekend.

Some times its as simple as tightening the retainer ring ...

Sometimes its the clicky boot , the nipple on the inside might need a small trim ...

Or its a contact issue , easy fix , or just a bad switch ... Cant say from here ...

If the tube goes all the way through, it's potentially the high quality kind (good finish that doesn't just come right off, etc), but the "classic" UF designs are copied so much it's hard to tell. The problematic ones I've had all have that "wall" (which is actually a nice feature since the battery doesn't flop around when you're changing dropins). The problem seems like a seating/contact issue. If reseating the dropin doesn't change anything, it's probably the switch. The tails are very easy to take apart w/ tweezers. Sometimes cleaning and moving things around slightly fixes.

The 502 is one of the my favorite hosts. Got that "industrial" quality to it.

Not much that can go wrong with a host other than the switch. I've had several that were loose and worked great once they were tightened down, but one I had to replace altogether. If it's not the switch, try doing a really good cleaning job on the threads and then use some dielectric grease on it.