Wow, those where darn good pics, thanks! Sorry I can’t help you with the memory issue.
It looks like it has two Alpha & Omega AON7520 “AlphaMOS” mosfets. I might be wrong on the precise model but that symbol on them is definitely Alpha & Omega.
It would be nice to know what that SVA11 / SVAII thingy is.
At the risk of exposing my lack of electronics knowledge: could those all be FETS? In which case, together with the two big ones, for each power setting a separate channel with FET is used (so no PWM) ?
The two large squares in the center are the primary FETs running in parallel for redundancy / heat spreading / etc. The medium sized three legged chip is the smaller FET that Mike mentioned, usually used for signal control or power under 2 amps. The 10 legged chip is a PIC-style MCU. It’s that 5 legged (SOT23-5 footprint) that runs the FET control show. It’s got to either be a current controller/regulator or op amp. I’m still mildly new to those. I’ve searched for hours to try and identify it, but no luck yet.
I did a lot of mods, upgrades, etc. this last weekend. One of my favorites is to this SK98 I've had sitting around for a while.
I 'helped' TA get rid of some LEDs and I used this 219C, 5000K on a 20mm DTP MCPCB to replace the XM-L.
I replaced an UltraFire 5 mode (H,M,L,Flash,SOS w/memory), 17mm FET driver in a C2 with a Convoy SST40 5A and used the old C2 driver in this 98. Sorry, no picture of that driver but I opened up the hole on a Nanj 20mm contact board, extended the driver's cheap spring, added another (from a bad SP32A driver) as a spacer, soldered the negative outer rings and then by-passed all that resistance. It can pull 6.7A with a Molicel P26A, ouch!
I found out that an S2+, lit switch fits and works fine with the Ultrafire driver. I don't want to burn it all out so I'm using 35Es (~5A).
And the 90+ CRI, 5000K tint is beautiful! with an 'almost' sharp-focused projection of the die.
I’ve tried some reflectors, and at least two TIRs,
some 3mil. some 5mil. XPL2,
some beers,
well today it’s aspheric, lens scratched up the most,
it’s not bright, wont reach far,
but still I must post….
3000k 5mm LED ground and polished plus some silver marker sloppily applied to kill an artifact
Head [dis]assembly.
Took me a while to realize how to make it turn on and off the original way, but it does.
I meant that typically aspheric lights are very inefficient when focused. Optically inefficient.
But 5mm LEDs come in narrow emission variants that could avoid most of the light losses. And despite the fact that the LEDs themselves don’t tend to be efficiency leaders, the whole setup could be fine.
I planned on doing a simple mod of switching out the butterfly XML reflector gasket on my clear S2+ to an XP gasket. The LED was perfectly centered, but I didn’t like how it looked.
When I took it apart, there appeared to be a gap between the LED MCPCB and the pill. When I removed the LED, the thermal compound barely spread. The wire holes in the pill were not chamfered enough to allow the MCPCB to lay flat so I sanded them down.
Everything looked good, but the Samsung LH351D 4000K 90+ CRI beam was still poor (though better than with the original smooth reflector). There were a lot of artifacts and I thought about installing a frosted lens. Then I noticed the reflector looked pretty smooth at the base given that it was OP. I had another spare reflector from a triple build and there was a significant difference between them in regards to OP and how the base spans out (left is the old, right is the new).
The new reflector made a huge improvement! My mod started out as simple, but after several hours I ended up with a much better flashlight.