Little power to laser

Hi I’m Now having trouble with Lightburn It used to work fine I’m still on the trial but it started a job and stopped half way so I deleted it and re installed it now the laser fires but at hardly any power all the settings are ok 100% In both GRBL and Lightburn I clean the laser after each time I use it with nail polish remover. Grbl is working fine when I was using lightburn I thought it is great but now ??? thanks Daryl