Thank you, yes all 4 of them blew the R48. I first suspected putting one of the diodes the wrong way but i checked and it was fine. Also running the board on 5V made the leds lit up so i thought it was ok to run 19V
@Agressivstreetlamp how do you think it is not aligned? programming went fine…
@Colip61 Yes, i would absolutely have used that, but i dont have an current limiting power supply. Its on top of my shopping list now.
No, i just put some flux on the backside. I thought about that but i was worried it will not sit flat on the pcb.
It’s hard to tell but I just looks like it’s too far to the right.
But I could be wrong.
If we had 4 ics at work that blew the same component under normal conditions we’d call it a job well done and hand it back to the designers and tell them to fix their shit. Cough Cough @shaman cough Cough
Except that they have been made by others and work already proving the design?
Not an E.E so perhaps other variables come into play like component quality, pcb quality. Whether the design has inherit fragility’s over a standard 4.12 I doubt it.
18v would not be a factor that’s for sure.
The solder job is not up to professional standards no offense @doomy but I guess why you’re asking. Maybe send in one of the pcbs for inspection by @shaman to see if there is anything to learn , avoid & share by all.
@magharees Yes I was just joking. But 4 boards with the same failure does not sound like a botched solder job. More like a misplacrd or bad component. Component quality definitely can matter but if as long as all the components match the same ratings you should be ok. Actually Alan, that’s brilliant! @doomy did you order the exact BOM or did you have to get any alternatives?
I’d say your solder work is pretty damn good for iron work. AnY 0603 that stays with an iron is an achievement. I apologise if it sounds like I’m bashing your work
I know that my soldering dos not look that nice. Its the first time i soldered SMD components other than a few resistors here and there. Maybe if i go over it with the hot air gun it will look better, but as long as it is doing its job im completely ok with it.
When i built the focers i had the original bom from shaman printed out and always double checked the values. I did this in total 3 times so im 99% sure the values are correct.
Martinsp from the builders forum built 18 of these for me and the beta testers. Each one was functionally tested by Martin before shipping.
The quality of assembly can make or break the product regardless of design and vise versa. It appears @doomy is trying his best with what he has but proper assembly is proving to be a challenge without a hot air gun for proper reflow. That ground pad underneath the DRV is difficult to solder properly without hot air which is why an entire hole was added to the updated design.
Remember @doomy has been trying to assemble the beta version. It not as DIY friendly as the full release will be.
Thanks a lot looking at it running Ack firmware on this FOCer.
@doomy Can you take a picture of the blown DRV back to see the ground pad? If there is any solder on there the connection was fine and not the problem blowing R48.
Too large of current flowing through R48 is causing it to blow. Whatever is causing the large current to be drawn is the issue. Not having the ground pad of the drv soldered properly will most likely cause the controller to fail.
I used a fairly hot iron and plenty of flux to solder the pad through the vias. However, solder paste and hot air will be the most reliable in your case.
There’s no way to check the connection without removing the DRV that I’m aware of.
