Bringing Imalent DM21TW back to life

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Lexel
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Bringing Imalent DM21TW back to life

So after the light dies just after one day, I got the message that a replacement light is shipped, not just the replacement tail cap which contains the defective driver

the full review can be read here
http://budgetlightforum.com/node/53339

I start with the mods I done when the light was working

At first I did solder the spring in right angle and added a spring bypass

Cleaned the old thermal paste

Cut the wires a bit shorter

added a bit of lubricant to the centering ring as the LED MCPCB has no screws or other secure to rotate when twisting the head to prevent the MCPCB from getting grip and rotate, which may lead to a short cutting in the wires
removed old ceramic thermal paste and added arctic silver 5

Also did the LED wires cut a bit in length and soldered them so that they prevent the MCPCP from rotating

Now to the clicky Mod part:

Opening up the press fit contact board
as expected it contains the bleeder resistor for the tail cap driver and a Diode for charging the battery from tail cap

removed parts from contact board and driver
TA Bistro triple channel driver ready

For ground contact I didnt want a wire for least resistance possible, so i reused some old solder wick

Positive driver voltage wire

The original reverse polarity protection is poor, wont work on most cells
But it does not make contact with double shrink tubed unprotected cells

Removed the black color as it got scratches and for better optic,
as I saw the insulator is only painted black

glued the insulation washer to the driver, unfortionally got some bubbles

added some silicone for heat transfer from the 7135 to the body, just to notice the silicone I had left was almost dryed out on most of the tube

and pushed the driver in the head,
you can see how they damaged the threads by pushing in the PCB, I filed off the noses on the PCB, fits now without touching the threads

When I saw the heat paste on the head and MCPCB I realized it could not sit perfectly flat in there
as the center was not machined down to the same level

2 touches with dremel fixed it

Now to the tail cap:

first opening the potentiometer hole up to 16mm for the switch cover

Then I cut off the top part of the tail cap

sanded down the tail, so it can tail stand
there are still 2 marks where the rotary base was screwed onto

Making a washer for the tail cap from a M6 30mm washer with my dremel
added later a 2. 0,7mm washer to get same thickness as a Convoy Washer

Soldered the switch to the stripped driver board
the pads with spring and body were on the right spots so no wires needed

I grind some charcoal to get the epoxy black

first layer on tail applied

gravity was my opponent too much flowed down
so added a 2. layer when first started to get solid, now the shape i wanted was achieved

removed the cover inside

Nor used my Dremel to get the switch hole

Sanding the first time

some bubbles opened up and I sanded down to the aluminum
So added a thin layer on top of this and sanded again
The switch cover fits perfectly

The original construction of the retaining ring was not how I like it
I wanted to gain more movement for the spring to get protected and unproteced fitting

First heat up to get the plastic insulator seperated from it

Sanded down the rim and another 0,5mm

I had to lift the switch a bit to press the switch cover against the tail

finally glue the switch to the board

Assemling the light and it works great
nice tint of the XPL HI warmer than the XHP35 HI E4-3C

Edited by: Lexel on 03/30/2017 - 18:35
teacher
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Very nice work! Thumbs Up

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Lexel
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Last seen: 12 hours 26 min ago
Joined: 11/01/2016 - 08:00
Posts: 2651
Location: Germany

added a clip from Convoy