[shazz]

I have had my laser for about 8 months now and have had no problem at all. I bought it from China. Today I went to use it, it had been about a week since I last used it and the laser won't fire. Does this mean the tube is empty and I have to replace it or would it be some other reason. The head still moves and goes along the path it is set but no laser at all. The meter doesn't register, nothing.

Please Help, I have a big show coming up and am short my pieces for the show. I can felt and this has been the only material I have ever cut on it.

[zax15uk]

Shazz,

The tube would need to have fractured to explain a sudden loss of power, you can visually check to see if water has entered the center chamber. That would be caused by mechanical or thermal stress, if for example the water froze or you ran the tube without sufficient cooling.

It is more likely a simple electrical issue related to the interlocks, switches or laser PSU.

Hope you find a simple fix.

Zax.

[shazz]

Thanks Zax for your quick response. I will check to see if it cracked. If it is electrical how would I fix that, would I have to send it to someone or is it an easy fix?

Thanks again!

[zax15uk]

If the tube is intact, I would check the interlock wiring. You can check for continuity as the switches are in series. There should be switches on the tube, laser and PSU enclosures.

The other place to check is the laser PSU, to see if any of the indicators are on (it should have 1 or more LED's, depending on model).

If the LED's aren't on at the PSU, disconnect power and look for any sign of burning. Be careful when the PSU is energized as it's high voltage.

Zax.

[austin.mn]

every once and again I have to lift the lid and close it again. You can easily here the switch click when it is opened and closed, but.... that is what seems to fix mine when it happens.

[KPBadger]

Hi Shazz

If a broken tube is not the problem, then another thing to check are the wiring connections to the tube anode and cathode - these can get a layer of corrosion which could be causing a problem if they are connected via clips.


As Zax says , be careful with the high voltage end and avoid touching any contacts around the power supply . Use a suitably insulated screwdriver! the PSU can hold a charge for a while even after switching off
- i gave myself a good shock from one of the terminals with a screwdriver when i first got the machine!



You can also test the low voltage from the controller card is OK as shown in the sketch, to rule that out. - obviously if you have a different card then you will need to look up the manual to see which pins are which.



As the others have said, a sticky interlock switch or water cooler interlock will prevent the laser from firing.


Hope you get it sorted - these things certainly choose their moments.


regards
KPB

[shazz]

Hi KBP,

Thank -you for all the info. I had my husband take a look ( I am horrible when it comes to electronics!) The tube is all good so we know it is not that, but it is blowing both fuses. So we are not sure what is causing it to blow the fuses (I know I am about to blow mine with this machine) . Do you have any idea what could be causing it to blow the fuses?
I think we might have to take it to an electronic store to see if they can fix it, which makes me nervous, moving it.

These things always happen at the worst times, although my husband put it in perspective, at least it was not when i had a big order to complete.

[KPBadger]

Hi Shazz

can you be more specific about the fuses ? where are they located?


Can i ask is the power for your extract fan / air pump / water cooler / chiller
piggy-backed from the laser machine? ( common with chinese machines as supplied ) or are they wired direct to mains supply.

If there was a fault with any of these auxilliary equipment it could cause fuses to blow if all the current is being drawn via the laser machine.


regards

[shazz]

There is a 5 amp on the circuit board and then a 6 amp on the side of the machine. Then the power supply to the cooler/fan ect is seperate from the machine.

Thanks again!!!

[zax15uk]

Where is the 5A fuse located? On the driver board or the laser PSU?

I would first inspect the board closely for any damaged components or traces, and check the wiring is all connected.

Then disconnect all the 'extras' (like the fan, water pump, lamp etc), the laser PSU board and the driver / interface. That should leave only main PSU.

If that works and doesn't blow fuses you can reconnect the driver board, and test again, then connect the laser PSU (which is most likely the problem) and keep going until you blow a fuse.

Once you narrow down the fault, you can take the board to a repair shop or fix it yourself. I wouldn't take the entire machine, except as a last option.

If the laser PSU is the problem, try an older TV repair shop or even a sign shop that deals in neon signs.

Zax.

[shazz]

Thanks Zax! Ok, I am going to sound really dumb, but what is the Laser PSU or a Main PSU? I do know the 5 amp is on the board.

[KPBadger]

Hi again,

First thing - to clarify power supplies.
Mains power comes in to the back of the machine. then is routed to two transformers or PSU's

1. the first transformer is a step-down to 24volt to supply the control electronics and motors.
It should look like a cigarette packet size in perforated metal.
There is no problem with it since your machine is working except for laser.

2. the second transformer is the laser high voltage supply. It is larger like the size of a half breeze block - this is the end where the problem "sounds like" it is coming from.





OK we've ruled out the aux. equipment,.

Next to rule out other simple things:-

With the lights off can you see and sparking or arcing?
Any smell emitting from the power supply?

Power supply LED ( on the large laser power supply ) i think should be ON when idle. and go off when the laser fires ( thats the way it is with my 60watt anyway)

The power supply unit may have an internal cooling fan - is it working?

( With the power disconnected ) Remove the cover from the power supply and examine for any obvious things - melted components.


If none of these things are showing any problem then wouldnt be able to suggest anything else without actually seeing it im afraid.


Hope its something realtively simple and cheap to fix.


regards


KPB

[zax15uk]

Mains power comes in to the back of the machine. then is routed to two transformers or PSU's

Power may come in from the right side also... but the routing is basically the same.

There is no problem with it since your machine is working except for laser.

I was wondering about that, has something changed? It appears the 6A external fuse is now blowing which would shutdown the entire system.

Since the machine was working except for the laser I suspect the laser PSU is the culprit, and should be relatively simple to replace and/or repair. What's confusing though is how it blows the 6A fuse once the 5A on the board is already blown. Maybe they replaced both, and they blew again... rather than just replacing the 6A and finding the machine powers up except the laser.

Zax.

[KPBadger]

Please see the attached diagram of a typical machine
(courtesy of XYZ-Exlas )

i hope this is of some help.



the motors have a dedicated 36v power supply in this case, not 24v
my mistake.





regards
KPB

[zax15uk]

KPB,

I don't want to negate any of your excellent advice or suggestions, which are all applicable in any case but I think they have the desktop model (of course I could be totally wrong).

It may not be a Rabbit or XYZ but probably similar.

http://www.rabbitlaser.com/products/hx40b-1.htm

http://www.xyz-tech.com/product.asp?id=41


The PSU for both machine and laser are likely open frame. The laser PSU would be larger and mounted in the base of the machine, and the system PSU on the side wall.

Concept and basic wiring is the same either way, except there is no dedicated PSU for the motors.

Zax.

[shazz]

Thank you, thank you, thank you!! This has been a great help. My husband said it makes sense to him. He said the 6A is not blowing anymore only the 5A (blown 4 times) while 6A is good.

If we need to replace the Laser PSU where can we buy one of those? Or would we have to take it into a repair store?

Thank you again for all your help!!!

[shazz]

Yes, it is the Rabbit!

[KPBadger]

My apologies Shazz - i hope i havent confused the issue.

I assumed that the components involved pretty much identical in the smaller machines. The principle is obviously the same but the components in your machine may differ in appearance from the diagram i have sent you.


In any case, it sounds like the laser power supply needs to be poked about at with a multimeter if there is nothing visibly wrong with it.
As Zax says, someone experienced with crt TVs and amplifiers would likely be able to take a competent go at it.


best of luck!

[shazz]

no appologies necessary, I can not thank both of you enough!! I have learn't so much and hopefully saved myself money and time as now I know what we are looking for and the steps to find out the problem.

My husband is going to take a closer look when he is home from work, I will let you know when we have it up and running again :-)

[KPBadger]

Hi Shazz - did you get anywhere with repairing the machine?

someone today has posted a thread with a photograph of the innards of HX40 machine - showing clearly the laser power supply as an exposed board in the base of the machine - not an enclosed metal box as i had expected.

Hopefully you got it sorted or are heading that way...~?


regards


KPB