You fixed it by reflowing the existing FET or by reflowing to swap on a new FET?
Doh you know I gotta start checking subs… It was actually quite a crazy ride on this one. I took off the old FET with a heatgun, put on the new FET. But then I was tired and hooked up the positive and negative backwards on the bench xd The diode was bypassed because I was testing what mods I could make to the board- so I had a wire going B+ to the cap, bypassing the diode.
I wanted to see if I needed the cap or not, as I don’t monitor that or write to memory on the Tiny13a- trying to optimize it for future builds xd If you will… Anyways The whole top end of the board started smoking. So I replaced the Tiny13a (checked out dead) and put in another FET as it wouldn’t fire up anymore. The stuff on the bottom all checked out. Then this is funny. I’m tired and solder fumes are giving me a headache. I clipped the led on, causing a short and shorting out the path. Turned it on to test- fried the diode (which I had just bypassed a minute ago).
Ok now I’m running out of parts. I put in a new diode and replaced the FET again just in case- it took a lot of juice through it with that short. Now my wife comes in and is like- what chu doing willis… Well Fing up
So I learned a lot that night, I really didn’t lose out. I learned what blows in reverse polarity. I learned what blows on a short. So now I have a deep understanding on what not to do and hopefully wearing a mask will let me undo the rosin flux damage to my brain
Hmm.
- Can you use pastebin or whatever you want to share the code you’re using which you think does not write to the flash?
- The C1 cap is always required, it’s called a decoupling capacitor or bypass capacitor - it has nothing to do with memory or the flash. The offtime cap is only required for offtime firmwares, not ontime or momentary. (I do not know if the offtime cap is used for dual-switch firmwares.)
- You fried the diode while it was bypassed?
- …or you unbypassed the diode and then fried it? Frying the diode with a dead-short from LED+ to LED- shouldn’t be possible I think.
- Rather than a mask for those fumes, ventilation is the normal solution. Also called fume extraction. soldering ventilation - Google Search
- Good thing these parts are cheap, right?
It’s all working now. Only fried the diode after I took out the bypass… Which is funny cause I had it bypassed a minute before clipping the leads to the led without a isolator put on the bottom of the noctigon xd
Yeah reverse fried the mcu with the bypass… Glad parts are cheap, and I learned a lot in the mess. Basically stupid stuff- I’m usually careful but get careless when I’m tired…
Thanks for the link on that cap wight :)… Was wondering if I could get rid of it. The code I used STAR Firmware by JonnyC - Source Code and Explanation
EDIT I see it the OTC would be under Star 3 OSH Park ~
- I still really have no idea what you are trying to describe. I’d like to understand how the diode got fried and nothing you’ve mentioned so far actually says what you did in order to fry it. :~
- I know (and hate) the feeling of making those stupid, careless mistakes while tired. You’d think we’d learn to avoid it! For my part I probably continue to venture into that territory because I’m stubborn.
- Ah, that’s right you did post it there! A momentary flashlight is really the only way you can have more than a single mode and refrain from writing to the flash.
Yeah I’m stubborn too when it comes to getting tired. Think my best ideas always come to me in my sleep. Like I used to wake up and write code that actually worked back in the day- same code I would be working on for two hours strait the night before with no results.
The diode, when I shorted out the led leads, forgot to put a piece of paper under the noctigon. Those MNKE batteries are supposed to do up to 32a- wish I didn’t throw away the bad FET from the reverse, it was melted on top lol
This is with an XM-L2 or something else? The XM-L2 thermal pad is isolated from both + and . In other words AFAIK you could attach either GND, BAT+, PWM signal, or whatever to the bottom of the Noctigon and not cause a problem. I do not understand what problem was caused by not using your paper isolator what do you have the thing resting on?
I clip them on with clips… It’s probably not a good idea now that I think about it. Put a piece of paper under the mcpcb so the bottom of the clips don’t connect. *EDIT oh I see what your saying- no it just makes a strait short between the two
I looked at the diagram and I couldn’t see how the diode went either… Think it would all go through the FET? All I know from experience is the diode goes if you short out LED+ and LED - on that driver.
Ahhhh, I understand now! I have my test MCPCB screwed to a very small heatsink, just solder wires onto it. Thanks for sticking with me until I understood.
Fair enough, it’s a mystery.
I guess… About half a volt makes it through the bad diode though. All I know is it’s stupid stuff… You shouldn’t be bypassing the diode, then on top of that apply power backwards… But somehow that happened. Then shorting the LED + and - when your tired shouldn’t happen either :bigsmile:
Good news is it’s done and the finished light worked great… Sent it out yesterday morning 
That’s the new U3 1A dedomed
