Second short circuit
Hi, i am assembling my first ratrig. I habe checked all the wiring for 10 times and got a short circuit. I thought the first one was because the transformater gave 27v. After that i chagend it to 24 measured everything out and got a new bosrd but i got the secind short circuit.
I attached two pictures of both boards (Bigtreetech Octoprint v1.1) I am not able to find out my problem.
Before i now get the third board and try it again i hope someone can give me advice what i need to check or how i can solve my problem.
41 Replies
rare-sapphire•12mo ago
so that is the U8 chip, it's a 5v and 3.3v chip
rare-sapphire•12mo ago
rare-sapphire•12mo ago
i'm not sure what it does though, trying to find that out
no idea, can't find what it is sorry
conscious-sapphire•12mo ago
I dont understand why he got the short circuit. Cause all 24v inputs are correctly set and i measured it out before. It seems like the chip got ve 24v
Also the little chip ne the power led got burned
rare-sapphire•12mo ago
could you send a pic of the wiring? with the PSU and board in frame?
conscious-sapphire•12mo ago
conscious-sapphire•12mo ago
The wiring is not cleaned on the last picture cause i was trying it first
conscious-sapphire•12mo ago
rare-sapphire•12mo ago
hmm, you've got the wiring onto the board correct from what i can see
conscious-sapphire•12mo ago
I hope so xD
rare-sapphire•12mo ago
it looks the same like mine, so i really hope so 
conscious-sapphire•12mo ago
Measured the polarity and w also before to be safe
rare-sapphire•12mo ago
i can't see if there's anything obvious jumping out at me
conscious-sapphire•12mo ago
How do you mean jumping out
rare-sapphire•12mo ago
something wrong that is easy to see with it
as far as i can tell it all looks correct
conscious-sapphire•12mo ago
What will happen if i power up electric without fans, stepper etc?
rare-sapphire•12mo ago
nothing really, it might throw an error without the steppers, but not sure about that
if you don't have thermistors in it will throw an error something like "ADC out of range"
conscious-sapphire•12mo ago
Does a short circuit protection exist? So i can protect the third board of short circuits and try it?
rare-sapphire•12mo ago
even if it does, you'll always be able to fuck it up if you try hard enough
my only suggestion is to take some time, and see if there's anything that is wrong, something's gotta be since it's killed 2 boards already
conscious-sapphire•12mo ago
conscious-sapphire•12mo ago
Look at the pin of the steppermotors. Allways the same.position looks like it is damaged
Maybe it is a production issue cause all are the same or this is the problem. Found on YouTube from teachingtech that these are used for sensorless homing for x and y.
rare-sapphire•12mo ago
oh yeah that doesn't look any good
or maybe not
rare-sapphire•12mo ago
rare-sapphire•12mo ago
did you remove the jumpers beneath the steppers btw?
conscious-sapphire•12mo ago
I put the jumpers like you can see on position 4
conscious-sapphire•12mo ago
U can see it also on 1. I took the stepper.out
In your picture the pins look the same like mine
rare-sapphire•12mo ago
indeed, though i see something else here, you do not have any jumpers on many of the fan ports, the top ones specifically being concerning as they are always on
rare-sapphire•12mo ago
that could be it, but i have absolutely no clue if that would cause any kind of short and magic blue smoke
conscious-sapphire•12mo ago
Hm i followed the steps on ratrig. Just put the jumpers for the 2 fans i am using (hotend and cooling)
rare-sapphire•12mo ago
i do think you need to have them on the ports you aren't using too, doesn't matter where
afaik, the RR docu says to move the jumpers you are going to use, leave the rest
conscious-sapphire•12mo ago
Hm ok ill check it again tomorrow
I’m late to the party, but the issue is clear. You have placed multiple voltage selection jumpers on several headers.
This connects 5V, 12V and 24V together. With 24V having the most „punch“, you’re overloading all 5V and 12V components… that board (and all stepper drivers) are dead
Also, you don’t need to place any jumpers on unused fan headers. In general remove every jumper that you don’t need!
yep..smoke city when you short all the aux p.s. together!
Saw that in the pic... had to wonder WHY he was wondering why he was smoking the boards.
as they say RTFM!
rare-sapphire•12mo ago
Ooh damn, didnt even see that! Too distracted by the mising ones!
conscious-sapphire•12mo ago
Thanks for the help. I just failed to look at this picture right. I thought the black ones are jumpers.
the 'black ones' as pictured ARE the jumpers... BUT you only put ONE in place on each fan port for which ever V+ supply voltage you want applied to that port.
rare-sapphire•12mo ago
to be honest, he's got a point, it can be easy to get wrong, specially when it's the first time you have this kind of feature
conscious-sapphire•12mo ago
Thanks for your help. This experience was lil bit expensive ^^
sorry to dig at you a bit, and it can be boring and tedious when all you want to do its get it up and running... even worse when you're not sure what they are talking about to begin with ..but to EVERYONE ... you really do need to RTM! Granted stuff is missed as developers already know the details, but if they put pen to paper, there was a reason for it!
...also in this case... would have save you a bunch of $$ in this case.\
conscious-sapphire•12mo ago
@mietzekatzi yeah it was my fault i know. But it is how it is. I am lucky that you helped me out.
Can someone maybe help with my new problem. 😅 i opend a new topic for it. I googled a lot but cant find the issue 😦