HELP! 50 watt blowing fuse only when firing,new power supply and Tube. HELP!!!

[Jeffrey Michael Wilson]

HELP!!! I was in the middle of a Job and 50 watt blue and white chinese laser....First time.....quit firing, but still tracked....just no beam. No door switches on this one, Emergency power switch bypassed. It would go through all the motions...just no burn from tube. Then Blew the main Fuse.....Replaced fuse, it fired and cut as usual....for a few seconds....then..blows fuse, no longer goes through the motions with no fire. Blown fuse..I figured probably power supply.....Got a new one.....put that in, and hooked up to old tube(mine was 5 years old....pretty good, still worked well) got it all set up. fired a few seconds, good clean no power loss ....then blew fuse. So I got a new tube today and put it in....did all the alignment///pulsed a few million times getting mirrors right...... no problems.....everything moving OK.... then did lines to set focal distance.... no probs....then got ready to do my test piece. I have the laser at 75% Max Power....... I was cutting wood at 5 speed and 95 power, in software program.....It went for maybe two seconds.....blew fuse, I put in another fuse....upped from 2 amp to 5 amp.... Turned the power down to 75 in the program, and 5 speed. It lasted maybe 3 seconds this time. Everything is well insulated, no popping or gapping or smoke or smell....just blowing the darn fuses. Pump and air seem OK......And it's only blowing when I am firing. I was in the middle of a big job I was already paid for.....this isn't Great.... HELP.....any suggestions would be vastly appreciated. I'm thinking next of firing at really low power, 10 or so to see if it blows a fuse.....running out of fuses....

[Clark Hussey]

My guess is you have a short between the fuse and your laser tube. Replacing 2 amp with 5 amp not a good idea.

[John Lifer]

Dude, go back to the 2amp fuse. NEVER go higher. But you have a short somewhere. I would expect you might be able to see the arc trace since you have blown several fuses. I would look close, and keep looking until you find it.
putting in more fuses won't make it go away. If you have ANYTHING plugged into the machine (assuming it has outlets on the back) REMOVE them and NEVER use those outlets. It might not be the actual firing but maybe just that whole outlet/inlet (as they usually are) that is the issue, a circuit in there that is shorted. But trace ALL wires and look until you find it.

[Jeffrey Michael Wilson]

Got it Fixed, hooked up the water and air assist on another circuit....and disconnected the internal light. Been working fine for 5 years, possibly the air or water pump are losing it and pulling more amps....but...HOLY COW, it's never cut like this before.. What I used to cut on 3 passes at 95% I now cut on one pass at 75% with laser set to 75% max.... Thanks for help....