[thebighorn]

Greetings,

I lurk here a lot but don't post much. Tend to learn enough that way, but not this time.

My Kitamura MyCenter/Fanuc 3M won't power up. I switch on main power and when I press the control power on (green) button I can hear a contact block engaging. After a duration of time, set via an adjustable timer, the contact block disengages. It had been the case that if I did this repeatedly the block would eventually latch and the control would boot up. Now the problem has worsened and, no matter how long I do this little contact block dance, the control will not power up.

Can anyone here help me trouble shoot this, point me in the right direction? What component/s should I be testing, etc.? All of my repairmen are unavailable until at least next week so I figure I should dig in myself...

Thanks in advance for any help you can provide.

Kind Regards,
James

[thebighorn]

It occurs to me that this may be a machine specific problem. That having been said, is there a more appropriate forum anyone would suggest? Other than the General Metal Working Machine forum, which seems pretty broad for my enquiry, this seemed like the best bet.

Cheers,
James

[Al_The_Man]

Often faults on this nature can be caused by the Power unit either not working or a short that shut the supply down.
The first thing I would check is measure the 5v or 24vdc out of the P.S. when powering up, if it comes up briefly, remove the 24vdc connections one at a time and see if the unit stays powered, if it does, it then track the source of the short on that conductor.
Do the same with the 5vdc.
Al.

[thebighorn]

Hi Al,

Thanks for the advise. I'm getting somewhere now.

I proceeded as you advised, removing 24V and 5V leads one at a time to no avail. With all leads removed I had someone hold the contact block manually so I could test output on the P.S. The 5V output is fine but the 24V is dead.

So now what? In your experience, is there any hope of repairing the P.S. or should I just replace the unit?

Thanks again,
James

[GPena]

That happened to me before, and as Al posts it was the power supply, they have a voltage detector very accurate and with a small failure it will alarm the unit. Depending of what model you have the problem could be located in different parts. A fast solution is to get one and replace it.

Greg.

[thebighorn]

I got the machine up and running a few hours ago with some Grade A shade-tree engineering. My operator mentioned that he didn't remember having this trouble over the summer, when it was hot. So I dug out a space heater and raised the ambient temp inside the control cabinet to 85 deg. F for about an hour and the P.S. came back to life.

The P.S. is certainly flaky and I'll definitely be replacing it ASAP. Just thought you might enjoy hearing about this rather unorthodox "fix". LOL

Sincere thanks to Al for his advice. I wouldn't have figured this out without it.

Kind regards,
James

[Al_The_Man]

I have never had much luck fixing switching PS, but it might be worth someone with some electronic background to take a look at it.
There is also a way to cheat the input unit from shutting down so you can check the PS.
Glad to hear you may have pinned it down anyway.
Al.