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.

living-lavender•7/9/23, 12:47 PM

so that is the U8 chip, it's a 5v and 3.3v chip

living-lavender•7/9/23, 12:47 PM

living-lavender•7/9/23, 12:48 PM

i'm not sure what it does though, trying to find that out

living-lavender•7/9/23, 12:55 PM

no idea, can't find what it is sorry

progressive-amaranthOP•7/9/23, 12:59 PM

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

progressive-amaranthOP•7/9/23, 12:59 PM

Also the little chip ne the power led got burned

living-lavender•7/9/23, 1:00 PM

could you send a pic of the wiring? with the PSU and board in frame?

progressive-amaranthOP•7/9/23, 1:02 PM

progressive-amaranthOP•7/9/23, 1:03 PM

The wiring is not cleaned on the last picture cause i was trying it first

progressive-amaranthOP•7/9/23, 1:04 PM

living-lavender•7/9/23, 1:04 PM

hmm, you've got the wiring onto the board correct from what i can see

progressive-amaranthOP•7/9/23, 1:04 PM

I hope so xD

living-lavender•7/9/23, 1:05 PM

it looks the same like mine, so i really hope so LUL

progressive-amaranthOP•7/9/23, 1:05 PM

Measured the polarity and w also before to be safe

living-lavender•7/9/23, 1:05 PM

i can't see if there's anything obvious jumping out at me

progressive-amaranthOP•7/9/23, 1:06 PM

How do you mean jumping out

living-lavender•7/9/23, 1:06 PM

something wrong that is easy to see with it

living-lavender•7/9/23, 1:06 PM

as far as i can tell it all looks correct

progressive-amaranthOP•7/9/23, 1:37 PM

What will happen if i power up electric without fans, stepper etc?

living-lavender•7/9/23, 1:40 PM

nothing really, it might throw an error without the steppers, but not sure about that

living-lavender•7/9/23, 1:41 PM

if you don't have thermistors in it will throw an error something like "ADC out of range"

progressive-amaranthOP•7/9/23, 6:04 PM

Does a short circuit protection exist? So i can protect the third board of short circuits and try it?

living-lavender•7/9/23, 6:10 PM

even if it does, you'll always be able to fuck it up if you try hard enough

living-lavender•7/9/23, 6:10 PM

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

progressive-amaranthOP•7/9/23, 6:28 PM

progressive-amaranthOP•7/9/23, 6:29 PM

Look at the pin of the steppermotors. Allways the same.position looks like it is damaged

progressive-amaranthOP•7/9/23, 6:30 PM

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.

living-lavender•7/9/23, 6:40 PM

oh yeah that doesn't look any good

living-lavender•7/9/23, 6:41 PM

or maybe not

living-lavender•7/9/23, 6:41 PM

living-lavender•7/9/23, 6:41 PM

did you remove the jumpers beneath the steppers btw?

progressive-amaranthOP•7/9/23, 6:54 PM

I put the jumpers like you can see on position 4

progressive-amaranthOP•7/9/23, 6:54 PM

U can see it also on 1. I took the stepper.out

progressive-amaranthOP•7/9/23, 6:57 PM

In your picture the pins look the same like mine

living-lavender•7/9/23, 7:23 PM

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

living-lavender•7/9/23, 7:24 PM

that could be it, but i have absolutely no clue if that would cause any kind of short and magic blue smoke

progressive-amaranthOP•7/9/23, 7:56 PM

Hm i followed the steps on ratrig. Just put the jumpers for the 2 fans i am using (hotend and cooling)

living-lavender•7/9/23, 7:58 PM

i do think you need to have them on the ports you aren't using too, doesn't matter where

living-lavender•7/9/23, 7:59 PM

afaik, the RR docu says to move the jumpers you are going to use, leave the rest

progressive-amaranthOP•7/9/23, 8:13 PM

Hm ok ill check it again tomorrow

Mietzekatzi•7/10/23, 11:31 PM

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

Mietzekatzi•7/10/23, 11:32 PM

Also, you don’t need to place any jumpers on unused fan headers. In general remove every jumper that you don’t need!

ptegler•7/11/23, 4:41 AM

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!

living-lavender•7/11/23, 7:02 AM

Ooh damn, didnt even see that! Too distracted by the mising ones!

progressive-amaranthOP•7/12/23, 2:40 PM

Thanks for the help. I just failed to look at this picture right. I thought the black ones are jumpers.

ptegler•7/12/23, 3:39 PM

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.

living-lavender•7/12/23, 3:41 PM

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

progressive-amaranthOP•7/14/23, 3:16 PM

Thanks for your help. This experience was lil bit expensive ^^

ptegler•7/14/23, 5:42 PM

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.\

progressive-amaranthOP•7/14/23, 6:17 PM

@mietzekatzi yeah it was my fault i know. But it is how it is. I am lucky that you helped me out.