Common fail: 808 nm laser no flashes? Black soot on bars = burnt stack from voltage spikes or poor cooling. See before/after: old 500W 10-bar vs. fresh replacement! ROMSHI fixes handles worldwide + sells stacks at factory prices. Remote consults! +7 918 011-02-34 (WA/TG) #808nm #DiodeLaserRepair #LaserTechnician #HairRemovalLaser #CosmeticLaser