Hi,
I think that I killed a BLF17DD while trying to get it into a pill, and it looks like I pulled the D1 on the spring side off. It’s still attached to a trace that got slightly pulled up.
Is there a way to repair this… maybe jumper that D1 somehow? Is there a schematic for the BLF17DD somewhere?
Thanks,
Jim
Can see the traces on D1… Looks like it goes from B+ > C1 and R1, through the board to Pin 8 (I believe) on the MCU.
RMM17DD_V2
Which version PCB?
It is version 1.0.
FYI, I got it working. It looks like the trace that used to be attached to the end that got pulled up was going to the positive battery pad (where the spring is soldered), so I kind of pushed the diode back, and then soldered a wire between the now-disconnected end of the diode and the positive battery pad. Here’s a pic before I cleaned it up (I filed the wire down a bit):
Amazingly, it worked!!
Thanks,
Jim
Thanks, comfy!
You can also just turn D1 sideways so that that end sits directly on the positive pad.
Fellfromtree, if you’re in the US pm me your addy and I’ll drop a couple v1.0 boards in the mail to you today. I bought a sheet of them (yes a sheet- 16x16 for 256 boards) and now that I’ve got my new design 3.0’s I don’t need these (gonna make an art project out of them).
Hi wight,
As you can see from the pic, I already “fixed” it. I had thought about turning D1 and soldering it as you suggested, but I didn’t want to stress the peeled off trace much, so I tried to position D1 as close as possible as I could to original position instead.
BTW, from the schematic that comfy posted, that D1 is between the Vin/LED+ to Vcc on the MCU What is that D1 for? Is it there to provide a feed to the voltage divider (the 19K and 4K resistors) for voltage detection?
Thanks,
Jim
In this particular design D1 is a “protection” diode. It prevents anything from happening if the battery is installed backwards since electricity will only flow through it in one direction. The MCU and voltage divider are both powered by the output of D1, which is slightly lower than actual battery voltage (say around 0.25v lower). In the future the schematic will very likely look slightly different. Take a look at the most recent discussion in Tom E’s BLF17DD Info Thread - Reference thread for more info.
As it stands with your driver you can stand to lose the entire trace all the way up to the via - just solder D1 from the top of R1 over to the BAT+ pad. Like you said though, you’ve got the problem solved and there’s no big reason to continue to mess with it. Maybe add a little glue if you’re not confident. I understand that it used to be common to glue IC’s onto PCBs.
Ok, thanks. And yes, I’m done futzing with this driver for now (As in “If it’s working, don’t break it” :)!)
Jim
Sissy… if it ain’t broke, fix it.
And if it jams, force it… it needed fixing anyway.
Hey CK, if you had any spares and could spare some extras, that would be great! 
I’ll assemble them and give them away for a project if everyone’s happy with it.
Sure, any interest in other sizes? I also have several dozen 10dd’s.
PM me your addy.
PM sent, thanks for your generosity!