For those in the US, it looks like Richard at MTN Electronics carries the better FET for $1.35. Is this the right one?
Yep, that one will work fine.
There are some nicer once that Lexel found recently that I did not know about when I first built these drivers as well for those that order from mouser / Arrow.
I just keep sitting on my coupon codes for these lights until I know they are good from the factory. What a rollercoaster ride. Lol
I have 10 of those. If I use two fet it will spread the load and iz is more safe think.
Removed the fet with regular soldering iron heated the top and the package turned in to dust. With a lottle help of pliers removed the top and insoldered the big pad.the pcb survived without any damage.
My good fets and hot air station are at work so I will put on the good tomorrow.
The only problem with using 2 FET’s is that the resistors are setup for a single FET and using 2 will cause them to switch more slowly and increase the losses (aka, they will get hotter) and cause the ramp to change some in the low modes.
You can try it and see what happens though but a single SIR800DP should work fine. That is how the lights I built are setup.
Ok then I will use one.
Thank you for all your help!
interested …any reviews
I’m at work now. Covered the surrounding area of fet with kapton tape. Added solder paste. And reflowed the fet.
Now it is blasting again 
Now I’m at day shift so when I get hom remeasure output and finally do an intensity measurement.
I hope swapping the FET is all it takes to make it bulletproof.
So you got about 18k lumen stock. Was that the NW or CW version?
18270 lumens NW version.
I’m glad there’s a happy end to this story.
Hmmm, I guess that means the CW that I prefer is what, 3k lumen less?
Still, 15k lumen is nothing to sneeze at.
No. CW is usually has higher lumens output.
Glad it is an easy fix. Has anyone replied you on the spare FET pad question?
Really? I vaguely remember the lower forward voltage on the NW giving it a higher output.
I’ll have to check TA’s driver thread. Wait, I’m not sure what exact CW emitter the factory is using. I may have to wait for a comparison.
Yes! TA answered it. It is designed for one fet only. Two fet will switching slower.
If you use the same bin then the output should be roughly the same between tines minus the lux meter bias towards CW tints.
In the case of the MT09R, I am not sure what CW LED’s they are using now but in the last batch the CW LED’s were a lower bin then the NW and were a fair amount lower output. Around 20% lower IIRC (so around 3 bins lower).
It is possible that they upgraded to P2 bin CW LED’s like I suggested for this batch though.
Oh, I also heard that they will be discontinuing the MT03 after this batch is sold out. I really like that light, the best flooder I own. Tempted to get another one if I could justify it.
^ That’s odd. Seems to me that the MT03 is a winner, and a Haikelite flagship as well…
My guess is they are consolidating the production into just the MT09R as it seems more popular. I don’t think the sales of the MT03 are good enough since the MT09R came out to justify selling both.
Aaaaghhh!!! Having flashbacks to the FIRST group buy!!! Lookout!! Terry is about to jump out from behind a tree and blame all of you for this issue!!
OK, that was unkind. Still licking wounds. That being said…what the heck Haikelite?? They just can’t seem to leave well enough alone. I wonder if maybe they were a victim of their own country’s nefarious business practices and settled for a cheaper FET which actually ended up being a crappy knock-off.
As a follow up - my first generation TA rework of the MT09R with its aftermarket high bin led’s, TA driver and spring bypasses is still going strong! 22k of clean, beautiful light. It scares my neighborhood every night when I go on my walk/jog.