Jetbeam PA40 ruined / need to unscrew heatsink

hiuintahs

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Guys, I ruined my Jetbeam PA40.

I have a Jetbeam PA40 with XM-L LED and I was looking at it thinking that I would change out the LED to a neutral white XM-L2. I was Just doing a preliminary look at what it would take to get into it and so I removed those two screws to see what they were all about. Well that didn't get me anywhere. I rotated the nylon disk which those two screws held down to see if it could come out and I guess I ended up breaking a connection under it between the spring and the LED (driver).

Anyhow, I ended up making the light not work anymore and I think I just have a broken connection. But that pinkish/redish aluminum plug which I'm assuming acts also as a heat sink would need to unscrew. I bent my snap ring pliers trying to budge it. Looks like its glued in well.

Right now the PA40 is toast unless I can get that pink heat sink out. Any suggestions?

gwxWoIr.jpg
 

louie

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I took my PA 40 apart and it was extremely difficult. I broke one pair of Wiha ring pliers, but fortunately had bought 2 pair. Heating with an electric airgun did nothing. The glue used was not like loctite, which softens around 450F. I rounded out the original holes and had to drill 2 more holes. I gouged the bejeebers out of the back of the pill. I used a decent tubing vise (aka a bicycle workstand clamp). Fortunately you can't see all the damage once reassembled, and I changed the LED out for a better tint. But it was the worst experience opening a head I've ever had. There should be a thread about my experience if you search. However, I haven't migrated all my CPF photos and edited my old posts yet.
 

hiuintahs

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Wow, no wonder it would not budge. Well I have an update. The nylon piece held down by those two screws was my problem. Evidently I had rotated it 180 deg and it was not aligning up making proper contact. After rotating it I was able to get light out of the head. But now I have another problem. Something has gone amiss with the driver which is evidently in the battery carrier. I can only get the low mode to work. I have no idea why that was the case except possibly when I had the nylon piece rotated wrong it was actually creating a short form the + to the - at the head. So now I've got a driver issue.

Out comes the driver

V0gVgUu.jpg


At this point, its turning into a science project. Not sure I will ever get it back together working but now I'm kind of interested in figuring out the driver. I cracked part of the inductor. I may have to replace that and use a guess as to its size. I noticed that it has a PIC12F629 microcontroller. I would love to get the code on that as I've programmed a few of those in the past so kind of familiar with them. I'm going to make an attempt at doing a schematic.
 

hiuintahs

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Louie, thanks for those pictures. I think I still would like to change out the XM-L to an XM-L2 neutral..........so may still try to get that head apart. I was looking at buying some right angle bent snap ring pliers just like those. As you can see my head already has a little marring around the holes and I fully expect it will get worse. I was also thinking of drilling the existing holes in the heat sink a little deeper before starting just so the snap ring pliers fit in deeper where the posts are wider for more strength.

I know you heated your head with a heat gun. Would you say that is still necessary?
 

louie

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If yours uses the same glue, I'd say heating it is useless and runs the risk of melting the centering device or contact holder disc.

My feeling is that it's too hard to apply grip and torque to break the glue with the pliers and depth of the head. You can see, I couldn't keep the pliers in while trying to apply torque (and not damage the black part of the head). I think I caused some scratches in the black part when the pliers broke. Afterwards, I filed off any projecting gouges and it all works fine.

If I could, I'd make a tool - like a short steel cylinder to fit into the head, with wrench flats (or use a Vise-Grip), and 2 (or 4 if you add holes) short pins on the end. Then you could safely vise it up, put a big wrench on it, and tap it with a hammer to break it loose. A lot of effort for one job.

You can try pliers, yours may be easier.
 

hiuintahs

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Ya, that is a lot of effort for one job. My brother has a lathe but I'm not sure how excited he would be to make me a tool. To hold the head, I think I will be ok with a strap wrench. The head is big enough diameter that I can put a large strap wrench on it and really hold it from spinning. The biggest problem as you have noted is getting something into those holes that you can apply enough torque without it slipping out.

Right now I think I'm going to focus on the driver. If that is successful, then I may rethink the LED swap.
 

HarryN

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Wow, no wonder it would not budge. Well I have an update. The nylon piece held down by those two screws was my problem. Evidently I had rotated it 180 deg and it was not aligning up making proper contact. After rotating it I was able to get light out of the head. But now I have another problem. Something has gone amiss with the driver which is evidently in the battery carrier. I can only get the low mode to work. I have no idea why that was the case except possibly when I had the nylon piece rotated wrong it was actually creating a short form the + to the - at the head. So now I've got a driver issue.

Out comes the driver

V0gVgUu.jpg


At this point, its turning into a science project. Not sure I will ever get it back together working but now I'm kind of interested in figuring out the driver. I cracked part of the inductor. I may have to replace that and use a guess as to its size. I noticed that it has a PIC12F629 microcontroller. I would love to get the code on that as I've programmed a few of those in the past so kind of familiar with them. I'm going to make an attempt at doing a schematic.

In theory you can measure the inductance, even in circuit sometimes.
 

hiuintahs

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I thought I'd give an update to this project........if you can call it a project. Basically, I killed the driver when I tried to get the head apart and left the leaf spring in the head in a shorted position such that when I gave up on trying to get the head apart and turned the light on afterwards............I ended up killing the driver because of that short that I didn't know I had.

It was easy to remedy that short but now I had a driver problem. When I got into the driver, I noticed that Jetbeam didn't scratch off the p/n of the microcontroller. I saw that it was a PIC12F629 and thought that I'd maybe reprogram it to work the way I wanted it. (ie: mode sequence goes up instead of going down). The other thing I though I'd like to know how to do is to program flash memory which I think is what they are doing to store mode memory.

But it all just looked like too much work for this type of flashlight, so I fixed the driver. (The switching p-channel mosfet was bad). The chipped inductor was fine. In the process I did draw out the schematic to the best of my ability. Not all parts were identifiable, but I could see the topology and figured things out. There are two boards in there. One has the microcontroller and control electronics and the other is the LED drive electronics. This is the schematic of the LED drive electronics:

tllaLGg.jpg


I replaced the bad mosfet and tested with makeshift LED and all is good. So I just ended up putting it all back together.

hJWIoFB.jpg
 
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