NEW CHINESE LASER BLEW UP WHEN PLUGGED IN HELP NEEDED PLEASE

[odinsminiatures]

for safety reasons what amp should the fuse be? i replace the old one with.
Glen

Ok Guys thank you so much I HAVE POWER, seems the connector to the power supply board was wrong way round, put all back together fitted new fuse and we have power and laser head moved to home position.
Also added extra ground wire.
will now set up the pump etc and see if the laser fires.
Excellent members willing to help out a newbie so awesome.
kindest regards
Glen

[buddydog]

I know it sounded stupid, but as im new to all this i did not know that there was a fuse located there, first thing i did was look for a fuse and could not find one and if it hadent have been for you guys helping me out and telling me where it was i would never have known where to find it...So thank you for that information, and yes the fuse is definitely blown.
Glen

Not at all stupid to not know if there was a fuse or where it is located. It is ignorance which is always where we have to start. I was "ignorant" on both of those things before Retro's post. If I would have had a blown fuse in my unit I would have found it (blown fuse) in 5 minutes or so with a continuity check (ohm meter). I would have been ignorant about if there was a fuse, ignorant of where there was a fuse, but "informed" about how to figure all this extremely basic circuit tracing out. I don't believe you followed the directions in my first post above (#3) or you would have found that your rear panel mains connector was open on one leg two days ago. We overcome ignorance with knowledge.

It would be nice to know if rear connector was injured when the short circuit blew the fuse? Continuing with my first post (#3) above, now we know for sure you had a short circuit (not an open circuit). DO NOT CONNECT THE UNIT TO THE MAINS DURING THESE TESTS. Replace the fuse and replace the (DISCONNECTED FROM MAINS ) power cord into the rear mains connector on the laser. With the switch "off" you should see continuity (1 or 2 ohms) between one of the power cord prongs and one of the input wires on the power switch (just connect one meter lead to one prong and poke all 4 switch connections one at a time and only one of them only should have continuity. Do the same for the other power cord "prong" and it will have continuity to the one of the other switch connectors. There should be no other continuity's any other way you test like across the prongs, The "other"switch connections, either prong to ground, any other place you test on the machine. I expect this first test to be good as explained since your original problem happened after you turned on the switch. With the successful conclusion of these tests we will know your power cord and rear connector and fuse and the input side of the power switch are all working as they should. Get this done and next we will test the switch, wiring between and power supply. Were almost finished with a conclusion we can have confidence in, your supplier can supply the right replacement parts for (probably just a power supply) and you will have enough information to convince him you know enough what your doing to get him to send one), and you can start stinking your house up with laser smoke!

Troubleshooting is a progressive and methodical series of tests that build to logical conclusions.

[buddydog]

Ok Guys thank you so much I HAVE POWER, seems the connector to the power supply board was wrong way round, put all back together fitted new fuse and we have power and laser head moved to home position.
Also added extra ground wire.
will now set up the pump etc and see if the laser fires.
Excellent members willing to help out a newbie so awesome.
kindest regards
Glen

Good deal Glen but remember we really need to bring this thread to a conclusion for others in the future who have this problem and search to this thread. What do you mean exactly "wrong way around"? I looked at my 110vac machine and the input connector to the power supply has 4 connections and the center two are the mains input. Flipping the connector would leave the mains in the same position? Mine is "keyed" anyway and wouldn't go on upside down. Was it the wiring to the connector that was wrong? A picture or a better description of the correct way might help someone else in the future. I may add some of this thread to a trouble shooting thread I started a while back.

[Retroplayer]

for safety reasons what amp should the fuse be? i replace the old one with.
Glen

Not sure if you still need the answer to this. Mine has a 15A installed (I thought it was 10.) That is the max the outlet is rated for (and your machine would probably become a bonfire before it ever reached that high...) so don't go any bigger than that. But a 10-15A fuse is more than enough. The machine probably draws closer to 3-6A max, especially at 220V.

And to double up what Buddy said, what did you mean by wrong way around? A good description of your findings will definitely help others in the future.

Glad you got things working!

[odinsminiatures]

Good deal Glen but remember we really need to bring this thread to a conclusion for others in the future who have this problem and search to this thread. What do you mean exactly "wrong way around"? I looked at my 110vac machine and the input connector to the power supply has 4 connections and the center two are the mains input. Flipping the connector would leave the mains in the same position? Mine is "keyed" anyway and wouldn't go on upside down. Was it the wiring to the connector that was wrong? A picture or a better description of the correct way might help someone else in the future. I may add some of this thread to a trouble shooting thread I started a while back.

After checking all the pictures i took of the power supply that i took before moving any wires, the connector was in the same way round, it does only go in one way.
Like i stated i did all the checks and could not find anything at all apart from the broken fuse in the power cord on the rear of the machine.
The only loose part i came across was a small piece of weld in the back of the housing, maybe this broke loose during transit and like you said worked its way onto the board and caused a short causing the fuse to blow.
Other than this i cannot find anything at all.
In a nut shell all i did was fit a new 15 amp fuse to the power cord inlet and remove the power connector to the power supply board and push it back in.
Ive tried the laser and its not cutting to well at the moment, i tried to cut a small circle from 3mm card as a test using power at 20% and it barely touched it, tried again at 80% using 3 passes and again it did not cut through not even half way
through. I'm going to test mirror alignment and see if that helps.
Glen

[Retroplayer]

Yep. Clean mirrors and lenses, check alignment, and also check to make sure your focusing lens is installed in the correct direction. Consensus seems to be to ensure the convex side faces the laser beam.

Also, make sure your piece is approx. 50.8mm (2 inches) from the lens (assuming yours shipped with the lens most people get.)

[odinsminiatures]

Yep. Clean mirrors and lenses, check alignment, and also check to make sure your focusing lens is installed in the correct direction. Consensus seems to be to ensure the convex side faces the laser beam.

Also, make sure your piece is approx. 50.8mm (2 inches) from the lens (assuming yours shipped with the lens most people get.)

Thanks for the information will do all the mirrors etc and do a test run making sure there is a 2" gap from the lens, then will post the findings.
GLEN

[buddydog]

Not sure what you mean by 3 mm card? 3 mm plywood? Yes definitely align mirrors and clean. I went as far as after aligning mirrors I removed the lens to clean and while it was out I put tape over the lens hole and checked for center of the "down"mirror on the head. Next check focal length by setting a piece of plywood at a slight angle in the clamp and then run a 3" line across it and see where the line is the narrowest. That is your optimum focal point. Break a tooth pick as a gauge to measure from the head mounting bracket to the work piece. After I finish some other projects I will have a cheap z table mod listed on ebay and a 3d printed air assist head. I have to write detailed installation instructions and it takes more time than I thought it would.