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i cant make this board to work help

i connect all in order (mini board) from video

i fup power connector (i pull 2 wires out of it when i disconnect it from nano) so i change wires to black connectors for each wire  and connect it in guide order  from usb connector  24v ,g,5v,L  that is from left to right looking at it

if usb is on right side ..  huh

and  when i turn psu on  i can manually click laster test it go to 4 ma and back

and that was it

no led light on board

i connect it 1st with usb out of k40  and i did not get led on

did i fup board or ?


a bit update i just read i for jumper ..so i switch to usb 5v and card start to work

it connect to lb but cant move anything

got alarm 8 i did on that $X and it unlock but no move $Y same

and i got error 9 now


got 20v from psu  (19.72-5) 4.92-5 from other)

when i do $27=3       switch x y  work

y motor start to humm but wont move  .do i need to test driver power level ?


i did move him in to x switch again and  ? and got this


and from now i dont have clue where to go


it show wrong pos how i see it but ?


now i did $27=4  (have these magnetic switches)

and i move in middle and left i engage switch

and did ?

i got this for respond


and home error 9 again

and y motor buzzz but not move  i guess y go down 1st and click switch then x

now to wait till someone get idea what to do

oh our all el appliances are grounded by default ,by law  they must have ground

so that was not problem ..

i still think maybe drivers send low power but ?

left was 0.61  right 0.65

i guess it was ok .. but why wont move   nano board work ok



Hi,  It seems a lot of things are going on all at once so better debug it systematically.

From the last message I see that the position is 4.00 (pull off is 4 mm) and the limits are triggered.

Have you tried to put the gantry in then middle of the work area and read out the limit switch statuses? If the limits are triggered then you might need to invert the limit switches ($5).

What version of K40 are you using (Ribbon or non-ribbon cable version)?

If you unlock, the motors still don't turn when you give command? (move arrows in LightBurn)

Ok let's see what your answers are so we can pin point it better

Cheers, PAul

Cheers, Paul awesome.tech


vref for drivers are same 4.69 v  on screw 0.6 and 0.65

on psu wire it's 19.6 v

i think this msg is from middle


did it again it show 4 not 480  for all 3 and rest is same

when i $x i press move left right it just say stream complete ok nothing move ..

so he get 5v not 20v

first pin is 24v from usb  i look again and it is and 4th from right  again usb side on psu

dont understand where it loose power



anyone know what to do ?

Hi, basically you established the issue being no power being delivered to the board. Now it is methodically stepping thru the various points with a multi-meter (volt) and measuring each till you find zero volts.

Starting at the connector on the board. After that you can measure on both sides of the PTC fuse on the board F2 and the step stick driver it self. See attached images for the location of the measuring point.


Uploaded files:
  • FuseF2MG.PNG
  • MeasurePowerMG.PNG
Cheers, Paul awesome.tech

F2 is 19.7 v

gnd on driver to vdd 5.1v / 5.11v

gnd on driver to vmot 4.75v /4.76v

what next ?


i look on reprap and polplu forums  cant find reason why driver dont have power


well atleast wont burn my finger again 🙂


so is anyone live in here ?

where i can find that f2 fuse ?

it died yesterday  ,,was have erratic 0 / 19 / 0 then just 0000


what are specs i need for f2 PTC fuse  ?

i find some like

63v 3a  and variation on 63v 1-5 a

ESKA SMD 1206 3 A 63 V

and 30vac 2a smd  from this site


and load from poland

this site


just need specs so can order one and replace it



sorry for late update i change drivers and steppers now work .. fuse is ok i guess and have power

just bad drivers  yeey

but now i have something strange goin on

he start homing and soon he hit y it wont to stop  just banging on end

what to do now ?



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