[jeff4freedom]

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) 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....

[b25p51]

Is there one or two fuses in the machine? If it has two which one, the one going to the high voltage power supply or the one going to the 24v ps? If, only one (normal setup) run a job setup WITHOUT any laser power for several minutes and watch the electronics for any problems.
Do NOT use larger amp fuses as that can cause more damage to the laser! If you don't see arcing/smoke, ect.run the same program again but with 10% power and watch everything again. Repeat again at 20%,30% till fuse blows.
If the fuse is the a/c power line do you have an meter that will measure a/c current? If you do (or can purchase/borrow one) install it to measure the a/c current draw and monitor it as you repeat the above steps starting at zero power. If you see the current spike as the fuse blows then there is a issue that I will need more info from you to chase down the cause. But if the current is basically steady and just go to zero, then replace the fuse holder itself. Sounds nuts I know but after 42plus years in electronics I've seen this happen more the once!