50w Chinese laser not cutting in Cut mode

[Kate Rose]

It could be wrong parts, wired wrong, bad controller or keypad or anything. I guess I have nothing else to add. If you can find someone in your area to troubleshoot, I would take it to them otherwise? When asking for help, list ALL the details.

Okay, thank you for trying to help.

[Dave Sheldrake]

SH350D

If the tube was dead and the PSU died then you may have a cascade problem. Did you run the new tube on the old power supply?

Was the new power supply adjusted to put out the correct current (at default they pump 35mA, ie: more than enough to kill your tube)

How long is the tube? from memory the 350 won't take a true 50 watt without an extension so I'm betting it's an overdriven 40 watt

Bill's right, at this point it could be absolutely anything electrical in the machine and/or badly aligned optics

[Kate Rose]

SH350D

If the tube was dead and the PSU died then you may have a cascade problem. Did you run the new tube on the old power supply?

Was the new power supply adjusted to put out the correct current (at default they pump 35mA, ie: more than enough to kill your tube)

How long is the tube? from memory the 350 won't take a true 50 watt without an extension so I'm betting it's an overdriven 40 watt

Bill's right, at this point it could be absolutely anything electrical in the machine and/or badly aligned optics

The PSU never actually died; I replaced it in the hope that it would somehow magically fix the problem. The new tube (800mm) was used on the old power supply and the new one, and the machine ran exactly the same with both. I made no adjustments to the power supply.

Thank you very much for your help. I posted in the hope that it was some sort of, "Oh, this is the problem, and if you do A, B, and C, it will be fixed" type of problem, but clearly this is far beyond my realm of knowledge. I'm going to see if I can find someone locally who knows about these things to come take a look at it.

[Matt McCoy]

The PSU never actually died; I replaced it in the hope that it would somehow magically fix the problem. The new tube (800mm) was used on the old power supply and the new one, and the machine ran exactly the same with both. I made no adjustments to the power supply.

Thank you very much for your help. I posted in the hope that it was some sort of, "Oh, this is the problem, and if you do A, B, and C, it will be fixed" type of problem, but clearly this is far beyond my realm of knowledge. I'm going to see if I can find someone locally who knows about these things to come take a look at it.

You might check YouTube for mirror alignment. Easy and cheap to mark off your troubleshooting list.

[Kate Rose]

I will, thanks!

[Dave Sheldrake]

@800mm the tube is just about a 40 watt, that may be the base of all your problems if the PSU is pumping too much current

[Bill George]

@800mm the tube is just about a 40 watt, that may be the base of all your problems if the PSU is pumping too much current

Looks to be one of those low cost eBay machines sold as 50 watts. Over driven tube and with poor construction. So it could be anything.

[Kel Kodama]

If you replaced the tube (which used to cut properly) and didn't realign the mirrors, then I would suspect that the mirrors are the problem. Also, try to install an ammeter (amp meter) to make sure you don't exceed 20mA, which is the maximum that this tube is supposed to handle.

[Dave Sheldrake]

If you replaced the tube (which used to cut properly) and didn't realign the mirrors, then I would suspect that the mirrors are the problem. Also, try to install an ammeter (amp meter) to make sure you don't exceed 20mA, which is the maximum that this tube is supposed to handle.

Try 16mA, 20 will kill a 40 watt tube pretty quickly