80 watt Chinese Red & Black just started powering off when going over 20% power

[Angie Tracy]

Been checking these forums since before I got my laser a couple of years ago - and this is the first time I've needed to ask a question.
I don't use my laser a whole lot, but hoping to get some stuff done going forward. Haven't had any real issues until this week.

I'll try to keep it brief:

Removed and cleaned lens the other day. Re-aligned mirrors - wiped them clean without removing them.
Everything working, but third mirror and housing getting very hot. (put blister on my finger)
Took mirror off the next day because it looked black.
Removed mirror from housing - figured it was ruined. Black and coated with gunk that would not come off with alcohol or even paint thinner.
Ordered new mirrors off Amazon. In the meantime, figured I'd try some of that orange paint stripper - smeared some on it. Went to rub it around some more after 5 minutes
Mirror completely clean and looked brand new. (this might be something to try before throwing away mirror-- I was shocked!)
Still not cutting properly.
Removed lens just to double make sure I inserted it right the day before.
Lens has a hole in it and is broken in 4 pieces.
Put in a new lens I luckily had.
Laser working as good as new. Power great - everything wonderful
Next day - doing some test cuts to update my material settings library since I had so much more power.
Was engraving and cutting test squares out of plywood and the word "test."
Engraving fine, but once it gets to CUT the square - powers off. The entire machine cut off like someone pulled plug
Tried again - same thing.
After much trial and error - it seems it runs FINE with no issues until it starts a layer above 20% power. Shuts off immediately over 20.
Watched meter. It runs at about 7 when engraving - The higest I could see it going was 14 - then it shuts off.

I've never had any problem running at even 70% before - now can't go over 20, which isn't enough to cut anything without multiple passes.

Tube looks fine, water staying cool - not noticing anything unusual anywhere - no burnt wires, etc.

I am hoping not to have to replace power supply, but want to make sure that's the problem before I do. I am at a loss. Even tried a different file just to make sure something wasn't wonky with that one - same thing. Anything over 20% and it powers down immediately. Even just sending a pulse.

Let me know if you have the slightest idea what could be causing this. I read about a fuse in power supply - I haven't take it out yet. Hoping it's something even easier than that.

Thanks!

Angie:confused:

[Bill George]

What is the Brand of your machine and I would start with where you purchased was it off eBay? Red and black is the color not the brand.

What have you been working with that creates black soot and what power have you been using? Do you have a DVM or something to check power with? A loose power connection might be the problem, it creates heat on that poor connection and then fails under higher power.

[Angie Tracy]

I'll check. I think they call them red & black because they don't have a name. I'll see what I can find. The mirror didn't turn black over time, it did it overnight. If anything, it could have been the masking tape I was using to align the mirrors, but I think there might have been a speck of something on the mirror that caused it to burn - or maybe the cracked lens was shooting it back up. No idea. ? The mirror is no longer getting hot since I cleaned it and put it back. Everything is working fine until I increase the power. Just wondering where that connection might be. To the power supply? Inside of it?

[Bill George]

I'll check. I think they call them red & black because they don't have a name. I'll see what I can find. The mirror didn't turn black over time, it did it overnight. If anything, it could have been the masking tape I was using to align the mirrors, but I think there might have been a speck of something on the mirror that caused it to burn - or maybe the cracked lens was shooting it back up. No idea. ? The mirror is no longer getting hot since I cleaned it and put it back. Everything is working fine until I increase the power. Just wondering where that connection might be. To the power supply? Inside of it?

Your going to need to check and tighten All the connections (with the power off) and be prepared to use a voltage meter. For support your going to need to contact the folks you purchased from or find the parts online.

[John Lifer]

I would suspect something in the wiring. Getting some sort of short that is killing the machine. Strange that it just shuts off. I'd unplug it and start with wiring at the tube and work back to the power supplies. Unplug and replug every wire into the controller and where screws, check them for tightness. Look closely at the incoming power connectors. Those can be pretty cheaply made and may short out. If you have one of the machines with extra outlets on the back, unplug everything and don't use those outlets. Clean machine, and then you may have to diagnose the power supplies at to are all lights working properly and at right time. You might could use an extra person to look at the power supply and controller are while you try the machine out and see if they see an arc when you go up to 30% power. (darken room might help) But Power supply may be dying and killing it all also.....

[Angie Tracy]

I found out that it is an Omtech machine. Was originally from Orion, but there is no name on the machine. I see that it is the same company. I may have a unit that came out before they started putting the name on it.

I saw a video that showed me where the fuse was and I changed that. I am working on something else right now, but will test it tomorrow to see if that did anything at all. If not, guess I'll go through all the wires and connections. I will also try to email the company and see if they've ever heard of such a thing or have any idea of an easy fix.

[Bill George]

I found out that it is an Omtech machine. Was originally from Orion, but there is no name on the machine. I see that it is the same company. I may have a unit that came out before they started putting the name on it.

I saw a video that showed me where the fuse was and I changed that. I am working on something else right now, but will test it tomorrow to see if that did anything at all. If not, guess I'll go through all the wires and connections. I will also try to email the company and see if they've ever heard of such a thing or have any idea of an easy fix.

I doubt if it would be the fuse they are either good or bad, as you either have power all the time or not, did you test?

[Jim Fenton]

Switch or something in the wiring.

[Jerome Stanek]

On one of my lasers if the max power and min power are not the same it will only cut at about 20%

[Kev Williams]

Just a guess, but based on the 'If/Then' scenarios, especially the machine shutting down when attempting to run above 20% power, the only thing *in my mind* that COULD shut down the entire machine is the main power supply. There's several "power supplies" in a laser; the stepper driver, the laser's power supply, and the MAIN power supply. If the stepper driver or laser's PS goes down, the rest of the machine likely won't go dark...

Just ran some 'what happens' tests on my 1390 Triumph. First thing I noticed is NONE of the 'failsafe' shutdowns effectively 'unplug' the machine:

--if the water stops flowing from the cooler, the machine stops and throws a 'water' error on its' screen, all else remains powered up-

--if I hit the Estop switch while running, then 90% of the machine goes dark; it stops and the machine's screen shuts off, and the lighted LASER switch next to the lighted MAIN POWER switch turns off-- BUT, the MAIN power switch itself remains lighted--

SO-- questions: Do you have lighted Power and Laser switches, and if so, what happens to each switch when the machine shuts down when trying to run at 70%? --and for that matter, what happens when you cut the water pump, and when you hit the E-Stop?

--I'm trying to determine if your entire machine is going cold or just the E-stop circuit, or..? **I'm not sure at this point** but it may mean the difference between the tube's power supply or the Big Kahuna power supply being to blame...

[Angie Tracy]

I'm going to fire it up in a little bit and doublecheck. Pretty sure EVERYTHING is shutting down. As a matter of fact, I have it hooked up to a grounded plug thing I bought at Lowes and I have to even reset that in order to get it back on. I think I tried to plug it directly into the plug without the extra thing, but I'll doublecheck and get back to you. At first, I thought it was the breaker box or that maybe because the air was running at the same time that it was popping a breaker, but that doesn't seem to be it. It's never been a problem in 2 years - and nothing has changed in the set up. I know that I unplugged the pump that was also on the special plug, and that didn't help, but can't remember if I plugged it straight into the outlet.

[Bill George]

I'm going to fire it up in a little bit and doublecheck. Pretty sure EVERYTHING is shutting down. As a matter of fact, I have it hooked up to a grounded plug thing I bought at Lowes and I have to even reset that in order to get it back on. I think I tried to plug it directly into the plug without the extra thing, but I'll doublecheck and get back to you. At first, I thought it was the breaker box or that maybe because the air was running at the same time that it was popping a breaker, but that doesn't seem to be it. It's never been a problem in 2 years - and nothing has changed in the set up. I know that I unplugged the pump that was also on the special plug, and that didn't help, but can't remember if I plugged it straight into the outlet.

What is a grounded plug thing? You had to Reset what??? Pictures would help but you need to be a paid member $6 Min per year.

[Angie Tracy]

Ok. I'm an idiot. Sorry, everyone. I was in tech support for many years and overlooked some of the most basic troubleshooting. The issue IS the grounded plug thing from Lowes. It's a big yellow plug that adds a ground (I guess) - You plug one end in the outlet, there's a big component in the middle, and then you can plug 2 or 3 things in the other end. I only ever had the laser and the exhaust fan in it. I did remove the fan and had the same problem, so because I was getting power, I didn't really suspect the ground plug thing. I just plugged laser directly into outlet and can cut at 70 with no problem. (Tried it with the plug first to test and it shut off immediately) Just made several tests and the machine is running fine. I've been using that plug thing since I got the laser, so I guess IT has a short in it. I will probably replace it since I am not 100% sure my outlet has a ground wire. ?? Sorry for the trouble - I am SO glad that's all it was. WHEW!

Southwire 2-ft 12 / 3-Prong Outdoor Sjtw Medium Duty General Extension Cord in the Extension Cords department at Lowes.com (https://www.lowes.com/pd/Southwire-2-ft-12-3-SJTW-15A-GFCI-Cord/5013157201) is the thing I was using...

[Bill George]

So the big yellow thingy is a GFI protected outlet extension and the GFI or circuit breaker was tripping. The Chinese are pretty clueless about our electrical system and that ground plug might be hooked up wrong in your machine.

[John Lifer]

You just have a bad big yellow plug, most probably. Since it is used, then the internal connector/s are not making good contact with your laser's plug. Extension cords can be like that. I've got one old one with three female outlets. Two won't half work as they are loosing contact. They are kind of like springs. once old, they don't make really good contact and as you pulled more power it failed. Replace it.

[Angie Tracy]

Yes. The next time I go to Lowes, I will get another. It worked well for over 2 years.