Mori Seiki SL25B with Fanuc 10 won't power on

Hey all,

We just got a Mori SL25B at work with a Fanuc 10T control. Got it placed and wired in and the control won't turn on - when you press the power on button, it closes the main contactor for a second, and then opens it again. Nothing is displayed on the screen (it's got an LCD retrofit).

There's hydraulic pressure so I'm assuming it's phased right. I've checked every fuse and breaker that I can see, and they're all good.

I've read the 10 Maintenance Manual but none of the cabinet layouts seem to match what we have, so I don't know where to start troubleshooting. I can't see an input unit anywhere, and there's only one velocity unit. I have 100V and 24V at the transformer secondaries, and I can't find any other transformers.

If I press in the MCC and hold it, the master board shows an alarm of "d" which as far as I can tell says the power unit isn't ready, but I can't find our power unit in the Maintenance Manual. Most of the troubleshooting info I can find talks about how the input unit controls the power unit, but we don't have an input unit that I can see.

Anyone have any thoughts?

There is a power supply to the control right next to the monitor inside of the cabinet on the front. I would check the voltage on that, not sure how long your machine sat but I'll bet the caps in that power supply are shot, I've gone through them before and machine ran great after for a long time.

One of my clients has the same vintage of control and his monitor JUST started going out, I rebuilt his power supply a couple years ago now so if yours has another screen already and the power supply hasn't been touched, it is almost certainly part of your problem.

That is my take, I would be careful about giving this machine power, I just had your exact control pop and lose everything because of a weak cap or something (I have yet to trace what went pop). Something of this age you would be wise to replace all the little caps at the very least as a preventative measure, but that is only my opinion.

Good luck, let me know how it goes.

Nerv said:

There is a power supply to the control right next to the monitor inside of the cabinet on the front. I would check the voltage on that, not sure how long your machine sat but I'll bet the caps in that power supply are shot, I've gone through them before and machine ran great after for a long time.

One of my clients has the same vintage of control and his monitor JUST started going out, I rebuilt his power supply a couple years ago now so if yours has another screen already and the power supply hasn't been touched, it is almost certainly part of your problem.

That is my take, I would be careful about giving this machine power, I just had your exact control pop and lose everything because of a weak cap or something (I have yet to trace what went pop). Something of this age you would be wise to replace all the little caps at the very least as a preventative measure, but that is only my opinion.

Good luck, let me know how it goes.

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Good call, I checked the voltages on that board and the 24V line only has about 10V on it.

I don't see any obviously bulging or oozing caps, or any other problems.. did you just replace every cap on the board?

Yes, I like United Chemi Con when they have a suitable replacement. For that board they do but you will find they are much smaller in size now.

Ok, we'll give it a shot and see how it goes. Thanks for the help.

Got it powered up, you're likely right about the power supply giving out but it also appears to have an intermittent open in the power supply cable, as it usually will work after you wiggle the cable a bit.

I have another odd issue now that it's powered up - it's throwing servo overload and pulse coder alarms, but also seems to think the spindle encoder is the X-axis encoder (if you spin the chuck, it changes the X readout). If you disconnect the X pulse coder, it says the Z is disconnected. Anyone have any thoughts on that?