Need confirmation

[mondo50m]

I have a 40w Chinese laser. It has been working just fine for the last 2 months. As of 3 days ago, the laser no longer fires. I have checked inside the electronics bay and the laser power supply does not seem to be coming on. There are no lights on the power supply. There are 120 volts to the power supply and the fuse checks out just fine with a DMM. The fan on the laser power supply does not even come on. The gantry responds correctly when I try to cut a PLT file, but the beam does not turn on. I am new here and am in need of some advice. I have contacted the seller and he is working with me, but he seems reluctant to make a decision on sending me a new supply. PLEASE HELP!!!

[Exsecratio]

If you have door interlock switches check those as they will allow the head to move but prevent the tuibe firing.

best wishes

Dave

[mondo50m]

Dave, Thanks alot for your reply.

This particular unit has no door interlocks. I just wnat someone to help me determine if the power supply is my problem. There is 120 volts going into the power supply, the fuse is good. There are 3 lights on the supply and none of them are lit, the cooling fan on the supply does not turn. It was working fine and all of the sudden stopped. The only thing that I noticed different about the unit is that the ground wire to the frame had fallen off of the connecting screw on the frame. I re-attached the wire and it still made no difference. Could that wire being off for a short period have caused a permanent malfunction in the supply? I am just lost on what to be doing and where to go next to get this solved.

Milt

[Exsecratio]

Electrics aren't a strong point of mine but as far as I understand that Black to the chassis is just a ground wire and *shouldn't* make any difference to the function of the PSU (it only comes into play when there is a dead short such as a blown tube).

Does your machine have a flow control detection circuit? if so the laser also won't fire if that is jammed or not working.

I'm leaning towards power supply to be honest but best to eliminate all the smaller potential problems first.

best wishes

Dave

[Tweakie]

Sorry to say this but I think it is your power supply.

Can you post a picture of your psu for identification ??

Tweakie.

[mondo50m]

Thank you, Gentlemen. This is a 'cheap' Chinese laser. There are no interlocks at all.

Milt

[Exsecratio]

I'm with Tweakie on this one Milt, I'd suspect the PSU is fubar. Cheapo Chinese PSU's are pretty easy to get direct if it's the model I'm thinking it may be (although yelling at your supplier for a new one will be a cheaper option)

best wishes

Dave

[mondo50m]

Yeah, the PS is my choice also. I have been in contact with the Mfg. of this unit. The problem is it is done via email as they are awake when we are sleeping. They are agreeing to send me a new power supply, but I need to bear the expense of sending the old one back. I do not know what the cost of that would be, but I do not feel I should have to do that. This is supposed to be under a 2 year warranty. I am still negotiating with them, so we shall see.

Thank you all for the information and the "confirmation" of what I suspected.

Milt

[Tweakie]

They are agreeing to send me a new power supply, but I need to bear the expense of sending the old one back.

It is my understanding that there is import tax on s/h electronic equipment into China so make sure it is only the postage you have to pay when you send the old psu back.

Tweakie.

[mondo50m]

Just found out that the company I bought the laser from is going to ship out my new power supply. I must ship them back the broken one. Through some research, it should not cost me more than $40.00 to ship it back to them using USPS, and as soon as they get the tracking number, they will reimburse me through PayPal. let us see how this works out.

Milt

[Exsecratio]

As a quick update Milt, I was out with a client of mine yesterday and he has just suffered a dead PSU, quite a surprise but he had the same symptoms as you. No warning or previous problem just a sudden and very dead system.
Although it was a happy ending as Chris Jacobs at HPC is out on a warranty call to fix it for him this week. UK buyers are quite lucky, HPC is a decent company to buy from and will usually resolve stuff quickly in the event of the occasional mechanical problem.

I spoke to him yesterday and discovered there is a red test button on the side of many of the Chinese supplies that can help is verifying if the PSU or tube is dead as well as a green LED.
No green light = dead psu or blown PSU internal fuse. It may be worth checking your PSU internal fuse before having the hastle of shipping it back to China?

best wishes

Dave

[mondo50m]

Thanks for you reply. I did check the fuse and it is ok. I also have the test button and the green light that you speak of, the light does not show at all and the test button does nothing. Being shipped out tomorrow...wait, it MLK day so the Post is not working here. It will have to wait until Tuesday.

Milt