Axyz 4008 electronics malfunction

All,

I apologise if this thread is in the wrong place and I if I don't use some of the correct terminology as I am self taught.

A year ago I bought a used Axyz CNC 4008. It had been converted to use MACH3 several owners before and it seems a reasonable installation and setup etc. I have been happily using the machine and teaching myself Vcarve/Mach3 and slowly correcting previous owners errors (eg, all limit switches, and home switches turned off).

On Friday I went to use the machine and I can get zero response from the X, Y and Z motors. Spindle spins up as normal. Mach 3 is working fine I think. The LEDS on the breakout board are on. It has power!! When jogging the motors the breakout board lights up and when the gantry is physically pushed Mach 3 registers the limit switches being activated. The individual axis motor supplies (I don't know the components name) of which there are four have two LEDS on them. These are not illuminated at any point.

It is almost as if the motor power supplies are not getting power but the machine has power everywhere else. I am sure this is a power distribution issue or maybe even a fuse/breaker gone somewhere.

Has anyone got any ideas?

Kind Regards

HF

I think your last paragraph sums it up! The symptoms suggest a loss of power to the stepper drivers, which would be where I start looking. Check output voltage on stepper power supply?

I have had a similar problem on my own (home-built) machine which I tracked down to a previously-unseen fuse on the PSU board. On replacing it, I found that the real problem was an internal short in the toroidal transformer.

Classic fault-finding approach (apart from "panic and start changing things randomly!") is to look at what works and what doesn't. Here, we seem to have everything except the actual motors working. None of the axes work, hence problem probably in something common to all of them. None of the driver leds are on which suggests power loss. Hence suggestion to check power supply, is it getting mains power, are there any internal fuses/breakers tucked away in there?

Thank you for the reply.

I followed the error back to the toroidal power supply on my CNC. It has a blown fuse on the PCB and when replaced it simply blows again. The power supply is a PS806-5 and I can't find one for sale in the UK.

If anyone has any ideas......?

Cheers


Kev

That looks suspiciously like the one I had with exactly the same fault. Turned out to be the transformer had gone faulty. If you can get the power supply out, it's easy to change the transformer and they are easily available. I used one like this. You might find the equivalent cheaper elsewhere but I tend to use Rapid as being fairly quick and reliable. Without being able to test the power supply, I am guessing somewhat at the problem but it's the most likely to blow the fuse immediately. I've found my original order, and it looks as if I fitted mine about 6 years ago and it's been running fine ever since.

A complication might be that the original power supply also has a 5V winding that may or not be used in your machine. It might be difficult to source an exact replacement transformer (unless someone knows better?) In my case, I didn't need to use it as I had a separate 5V supply but you need to check. Photos of the power supply and its connections would help. Worst case, a separate 5V power supply is easily available for under a tenner.

If you can supply any additional info - like some clear pictures - then I or probably a number of others on this site would be happy to guide you through the next steps. I suspect that electronics might not be your strong point, which very much puts you in the majority around here! Don't worry - help will arrive. You should be able to fix this quickly and for a lot less than a identical replacement - if you could find one...

Thank you Neale for your replies. The Toroidal transformer and PCB are the problem. I have disconnected the x4 stepper drivers and changed the fuse. Blown fuse. I disconnected the PCB from the Transformer and changed the fuse. No blown fuse. I assume now it is the toroidal transformer.

The toroidal transformer has this sticker on it.Attachment 30892

Attachment 30893
Attachment 30894

So I think I need to source a Toroidal Transformer and all should be well. I have sent messages to both Airlink and Rapid. The transformer is 500w 58v, 48v and 12v. If I have to power the 12v separately I can. I am assuming the 12v powered the breakout board as the breakout board worked with the transformer attached and it was dead with the transformer detached.

If anyone has any more suggestions for where I can buy such a thing that would be great.

Kev

A few extra checks you might try to confirm the diagnosis:

Try a slow-blow fuse (if you aren't using them already). Transformers take what's called an an in-rush current when first powered which is higher than the normal running value.

Look at the capacitors. If any of them have a slight bulge in the end they should be replaced, though if one of them is faulty enough to blow that size of fuse then it would probably have detonated by now!

Disconnect all the transformer output connections making sure not to short any of the wires then try it.

You may have done all these, but buying a new transformer only to find the fault is still there would be no fun.