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No Power regulation (allways full power)

Hi, I did the wiring like in the installation video and description. Everything works except the regulation of the Tube Power ?
I use Lightburn with:






(Softstart, milliseconds)










(Spindle freq. 0 to 15)




and checked the Laser Power Connector for bad Ground. With POT instead PWM  on IN all works fine and I can regulate the Power. Tube is new
Any Suggestions

Before buying everything was looking so easy 😉 But for me it isnt.

What JUMPERS on the MiniGerbil Board have to be set ? I have one on JP5 (new Board) but every Picture i found in the Web doesnt have a jumper there ??


Thx in advance


Uploaded files:
  • MiniGerbil_Board.jpg

Hi Wolfgang,

There's no need to change the jumpers on your board.

Without reading through your $ settings one by one, the quick question is whether you've changed them from defaults listed under the heading defaults in https://awesome.tech/what-are-settings/

As background on laser regulation, once the Mini Gerbil is in place and the POT connector is replaced with the PWM wire, the K40 front panel no longer controls the laser strength.  The laser is now completely controlled by your software (such as Lightburn).  The POT connector must not be connected at the same time as the Mini Gerbil's PWM wire - only one system can control the laser at a time!

When you say 'no regulation' do you mean the laser is stuck OFF or stuck ON? Here are three possibilities for stuck ON:

a) LO (Laser Enable) connection is not properly connected - I have seen as even a hair thickness gap between the large 4 pin connector and its socket result in a poor connection.  Please remove and reinsert to ensure there is no gap.

b) PWM wire connection is not properly connected - please check the PWM wire is wired to the power supply, taking special care to remove the original POT connection to the power supply as per the instructions.

c) K40's often have grounding problems , please see

If you mean stuck OFF,

d) Check use of laser software.  For example, Lightburn has multiple settings required to actually send laser output.  Confirm the Mini Gerbil’s blue LED is illuminated, showing that it is outputting the Laser on signal.

e) Laser enable (LO) miswiring - see point (a) above

f) Check sufficient laser power.  Laser tubes have a minimum power threshhold to operate.  This may change as the laser ages.  Increase the laser strength output in Lightburn.

g) Address grounding problems see item (c) above

Please let me know how you go.



Found my mistake

$31 must 0 (Zero) if I switch $31 to 0 everything works like it should be ??

Cheers Wolfgang


PS: I have no idea if it is right or wrong. It just works 😉

Hi Wolfgang,

indeed the $31 minimum speed, should not be 1000 otherwise the laser won't put out any signal.

$30=1000 (Maximum spindle speed, RPM)
$31=1 (Minimum spindle speed, RPM)

Cheers, Paul

Cheers, Paul awesome.tech

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