Need help with Chinese Laser

[Jeffrey Michael Wilson]

Hi, I have a 50 watt Chinese laser. Haven't had it very long. Today I was burning some things, then all of a sudden....no laser. Like no power to laser. Power supply fan and light working. I'm wondering about the water sensor. I have the brass and silver red cap kind. I'm wondering if maybe it quit working and this shut me down. Would the power supply still be fired up if so? And could I cross the two wires to bypass it to see if that is indeed the problem? Any help would be appreciated...doubt I'll get much from the company I bought it from... Not much luck with that so far.... Anyway any help/suggestions would be appreciated... This is my livliehood... we don't have a lot of money so I can't just go out and buy parts willy nilly to see what works... Please help.
Thanks

[Chris Corwin]

Time to get the screwdriver out and start tightening the screw terminals on your laser power supply. Just unplug the power from the wall and wait 45 min for the power to drain from the internal capacitors before you try it.

[Dave Sheldrake]

Hiya Jeff,

The water sensor on Chinese machines are a normally open switch, just bridge them.

Have a look on the PSU to see if there is a test button, that bypasses everything and with the control card unplugged will fire the tube no matter what interlocks or pad problems there may be

[Chris Corwin]

Hiya Jeff, The water sensor on Chinese machines are a normally open switch, just bridge them. Have a look on the PSU to see if there is a test button, that bypasses everything and with the control card unplugged will fire the tube no matter what interlocks or pad problems there may be

Good advice. I forgot about the test button. That should narrow down the problem.

[Bert Kemp]

Also check the cover safety switch, one might have loosened up and dropped out of postion.

[Walt Langhans]

I've had my laser not fire for pretty much ever reason you can have, but it's more than I care to type I've sent you a PM with my number you can give me a call and I can walk you through some things.

[Jeffrey Michael Wilson]

Thank you, I'll try

[Jeffrey Michael Wilson]

Thanks Dave, I tried both of those things right off, but still no fire. My test button actually is labeled "TEXT".... Had me pretty confused for a while...."WTH, TEXT?????" Thanks, what I want to find out now is between the power supply or tube. The power supply light comes on, fan works.... but not sure how to test it.

[Jeffrey Michael Wilson]

I wish, but it doesn't have one...... Thanks

[Jeffrey Michael Wilson]

Thanks, I'm just now sort of figuring out this Forum how it works, wish it would email me when I get a response.

[Jeffrey Michael Wilson]

OK, this is the actual laser http://www.ebay.com/itm/CO2-LASER-EN...item23262d7182,
This is the tube that fits....http://www.ebay.com/itm/50w-CO2-Seal...item25752e7b19.. any others from other companies are too long for my machine....
So the only tube I found that fits says it's for a Shenhui DC-G350 engraver.... I'm wondering if this is the machine I have? So basically I bypassed the flow switch, no change, disconnected the one 6 prong clip going into power supply and hit the test button (says TEXT on mine, weird)...no fire... I'm leaning towards the tube being the problem, but have limited resources and don't want to buy it, then need a power supply too. Also when I received the machine Nothing came on at all.... messed with the Emergency switch...then all OK. At least that is how I remember it. Walt has 2 power lines coming into his machie and the emergency switch just shuts off the laser. Does anyone have my actual machine and know anything about this. Everything else on it works, just no fire. I've been using a 5 gallon bucket of water w/ Blue Ice for cooling..... maybe that isn't enough. The highest power I run it is 89%, never for more than 10-15 minutes and that is doing multiple pieces so that it can rest in between. I really need to get this going as I have a big order coming up ...... Any thoughts or help would be appreciated. Thanks

[Bert Kemp]

Is there a power cord coming out the back thats suppose to connect to a chiller make sure this did not come loose, if no cord then there might be a jumper bypass thingy that came disconnected if that happened the test button on the powewr supply won't even work.

[Dave Sheldrake]

To use the test function (text ) you have to unplug the PSU from the mainboard (you can do it with a bridge but it can be dodgy)

cheers

Dave

[Bill George]

I find it difficult to read a post with large bold type, small bold type and now small enough its hard to see text. Your jumping all around and not following any logical troubleshooting procedure. Also seems like your answering private emails or PM's in the forum??
It could be as simple as a safety switch on your machine, water flow switch or any number of things. But if you want to start by replacing the tube.....?

BTW Chris gave you some good advice about tightening screw connections, did you try?

[Rich Harman]

If it were a problem with water flow then there should be an error message on the LCD stating as much. Have you used the "Test" button in the past? If not then it is possible that the laser is set to fire (when using the test button) for such a short period of time that it is not noticeable. In the LCD menu, 'Laser Set' should be "0" if you want it to fire for as long as you hold the button down.

If the tube were bad then I would expect there to be a popping or arcing noise when attempting to fire. I have had only one tube fail on me but as far as I know, tube failures generally happen over a period of time - not instantaneously.

If you were to post photos of your main board, PSU, tube - anything relevant, it would help us to help you. A video would be even better.