I upgrade to mini gerbil ,don't work need help

maker forum is dead so will ask here
i unplug sbase and replace her with mini gerbil board
all was fine board light same like in guide
i get 5v power over usb ,i get 20v from psu to board
when i switch to lb board connect just fine
when i press home y motor just humm but wont move
drivers are on 0.6 and 0.65
and in terminal i get error 8
what to do now ?
i know it’s some tinny error but ?

@pauldg123 tag

Hi Kruno, I have provided some tips to try out. Best is to work on one issue at the time to pin point the root cause. It can be a loose power or ground connection, so measure the voltage on the stepper drivers (VMOT pin on the edge). Normally it should measure 24 Volt.

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i get 4.6v on drivers on vref --ribbon type
in middle i get 4 4 4 and no triggering

now to find out where it loose power … on connector from psu i get 19.6 v and on board pin same
pin from usb 1st

anyone know what to do ?
how to fix that driver get 20v ?

Hi, best is to measure before and after the PTC fuse F2. I suspect that it has blown since there is no power at the VMOT pin on the stepper driver boards (2 x A4988). If it’s blown you can replace the fuse and try to find out what the root cause is. Maybe one of the stepper driver boards has short? Measure without stepper drivers and see if there is 20V DC at the socket (Pin VMOT).

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update here too
i measure volts on f2 fuse , vdd and vmot on driver a4788


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 ?

this site have laag i post this in friday not today :slight_smile:
well f2 is blown it work then nont … in short it stop to work …i get yesterday readings from 0 to 19v in intervals every 4-5 sec and nothing any more

so where to find that f2 fuse

and what are specs for that PTC fuse ?


which one i need to buy for this f2 ptc fuse ?
anyone knows ?

Once @pauldg123 sees this I am sure he can direct you to the correct fuse to buy.

The reset-able fuse is rated 0.75 hold/1.5 trip Amp example SMD1206B035TF/16, I do have a few spares laying around so email me your address and I will drop it into an envelop. Are you sure it is the fuse? What caused it to blow? Normally they do reset themselves after the shortage is removed (defect stepper driver?).

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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 ?

i guess sequence is to hit y 1st then x axis or by looking he need to go left with lens head
i did $5=0 to change but wassnt that
when i manually move all in home position and type $x say unlocked $y say error 2
on ? i get this msg

That means the machine is not homed. You can use gcode command g92 to set the zero manually. I would suggest to test the limit switches. Read them out via the ? Command and active and deactivate them.

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x switch laser head lip is under i fix that and i get this when she is inside

after that i run cut of circle and i get this
On or near line 0:
On or near line 0:
Stream completed in 0:00 i draw circle in lb near home 10mm of
after that i re read machine codes all are like on guide this one too $5=1
and when x is inside of switch when i press home it travel from y switch by 20mm toward me
till it hit opposite side then i type $5=0 and home crash in bed but right way
they work by ? request but something else is fuped …
dont have clue what
Grbl 1.1f [’$’ for help]
Grbl 1.1f [’$’ for help]
[MSG:’$H’|’$X’ to unlock
(ATC M6, pulse/ff)
(ATC Tool Td, milliseconds)
(ATC M6 Td, milliseconds)
(Softstart, milliseconds)
(Spindle freq. 0 to 15)
(x:mm max)
(y:mm max)
(z:mm max)
(a:mm max)
(b:mm max)
by ? it say it is homed but lb wont run anything without error 9 or alarm 9

is it possible to turn off homing and use laser head from spot i move her manually ?

Yes it is possible to manually set a zero start point without homing. You probably have to issue G91 command to tell the machine it is st zero.

ah so i need export gcore from lb then edit and type G91 so macine think it’s in home
before all other codes ?

but why board dont do homing ?
by ? if i manually push in optical switches read locked .and later give only code 9 errors and wont run ?