Shenhui G350 Laser Machine does not turn on PLEASE HELP!

[Christian Soto]

I have two Shenhui Chinese Laser Machines (G350 50W) and my newest machine that is a year old does not turn on whatsoever. I was engraving a job when all of a sudden power temporarily went out to the machine but came back on in an instant on its own and the machine went back to home position. I restarted the job immediately thinking it might have just been a glitch but half way through it turned off and would not turn back on.

When I mean it "wont turn back on" I mean the whole machine such as the main power, laser, water, and air switches. I understand that the laser, water, and air cannot turn on without the main power switch being flipped but when I plug the water and air directly to the wall, they both turn on. I looked through out this forum for answers but only found people having tube problems along with their power supply. I do not think my tube is the problem mainly because there is no structural damage and it had been working perfectly for over a year. I also swapped the fuse located under the power cable connections with my other machine and that didn't solve my dilemma.

My thoughts are that it can be the switching power supply or the laser power supply. But since I am getting no power whatsoever to the machine I am leaning towards the switching power supply. Has this happened to anyone before? Please help before I go purchasing all sorts of parts that I may not need.

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[John Lifer]

You have power issue. I'll assume you have a multimeter, if not and don't know what I'm talking about, stop and find someone who can help you do basic troubleshooting.
If so, start at the wall outlet checking for power moving towards the machine and into it. From your description it sounds like it might be the power supply. Since your auxiliary equipment isn't working, check where that power comes from first.
If it goes thru power supply, then it might be dead...... Good luck and DO let us know what you find. It might help someone else. :)

[Scott Marquez]

Check main power at the wall.
Trace power coming into the machine.
If power is coming into the machine, trace it through the Emergency Stop, this could be burnt out, which has been a common theme with these machines.
Ensure E stop is not engaged, this has happened to more than one operator.
Scott

[Christian Soto]

Its not the emergency stop as this has happened to me before where I accidentally press it but now I always check that first. I have been doing this for 3+ years now. Also, it is not the wall outlet because as I have stated in the OP, when the water and air pumps are connected directly into the same outlet as was the machine, they both turn on and function properly.

I had thought that the power supply (the larger metallic box) was only for the laser so I am leaning towards the switching power supply that leads into the machines controller box. I believe the switching power supply also powers the stepper motors as well. I took it apart and found very poor workmanship (made in china). The balling done underneath looks terrible and the fuse that is soldered to the PBX board does not look burnt. I am going to Fry's Electronics to get a new one. I will post my findings on here later today when I reconnect the new unit.

Cheers,
Chris

[Tony Lenkic]

So if power is at wall outlet next thing to look at is plug end at the machine. Is power cord bringing power to the machine. If you have a multimeter you can unplug cord at machine end and varify power is there.
In some cases that plug/receptacle at machine may have a fuse built in it. If all is good than you may have issue with power supply unit in side machine.

[Jerome Stanek]

Check your plug some lasers have a fuse in the plug

[Christian Soto]

No fuse in the plug. This is the type of connection where a universal 3-pronged power cable is used. I installed the new switching power supply and that didnt work either. My machine has absolutely no power or indicator lights that turn on. I tried different outlets, cables, fuses, and now a switching power supply. I will now have to throw away $150 on a laser power supply and hope that fixes my problem.

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[Bill George]

You received some excellent advise about purchasing a multi meter and start at the power source where it comes into the machine and start tracing it back. You can keep guessing and replacing parts and do whatever you want. Did you check the connections where the power cord comes into the machine? I have been an electrician more years than you have been alive more than likely. But what do I know??

[Kev Williams]

Ditto on checking with a multi-meter.

You state it's not the E-stop button because you check it-- Ok, making sure it's in the "on" and not the "off" position is "checking" it, but have you checked the to see if the E-stop switch itself is bad?

--This is why you need a multi-meter, or at least a 110v test light...

Here's one I haven't seen mentioned: Maybe the $3 ON/OFF switch is bad... They're made in China too... ;)

[Wilbur Harris]

The fuse may be difficult to see. I have a Shenhui laser and the fuse is just below the main power supply plug...you can't see it if the plug is in and then you have to know it's there. Unplug the machine and look just below the plug for a fuse "pull out".
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OOPS! Re-read your initial post and you said you checked those fuses...