T-32 emergency stop. Can't find the cause.

Hi. I'm stumped. Machine is an old quickturn 28N. I've owned it for about 15 years.It's like my best friend. We've had our ups and downs. All the drives have been changed over the years. Power supplies etc. It's always thrown alarms and been easy to diagnose (with a lot of help from this site).

What's happened this time
- it sat powered on for a day, nothing was wrong. It was powered down, sat for the morning and was powered on to start work, it had an emergency stop 128 alarm on the screen. All drives show E7 and we haven't been able to get rid of it. The emergency button is good and was changed out just in case. There's 24volts down to the control panel and to the drives. We spent a few hours on the phone with the mitsubishi techs and after going through the M300 servo disable system the techs are mostly positive it not the drives or the control. They feel its a problem down stream. My only problem is I'm pretty sure if it was, there would be an alarm however if it was a drive there should also be an alarm.

I've read and searched hoping to find an issue but everyone else seems to have the normal second code or drive error on the drive.

What Ive tried so far - pulled the lubrication unit, clean its filter checked its power and the sending unit
-disconnected all the encoders and servo motors, then re connected
- checked the home position sensors.

Is there anything else I can check? It doesn't have a bar feeder, parts catcher, conveyer etc..

does anyone know the address in the diagnosis screen to see if the drive is seeing the e-stop?

Has the spindle drive FR-SE or FR-SF powered up?
There is an LED inside the black power supply at the top.
This should be lit before powering the control up.

Bill

The power supply (SF-PW) has an amber LED towards the left side if you look under the housing before you power up. The spindle drive has one red and amber LED and on the digital read out it shows a a vertical bar with a horizontal bar like this I- but not an I and connected. The x and z drives show A7. Once powered up the red LED on the spindle drive turns off and the amber one stays on. All three drives display E7. Which means its the Emergency Stop is engaged. But the switch works. The E-stop circuit and the ready circuit are closed all the way to the end of the CON1 connector which attaches to the bottom of the spindle drive board. The door safety switches are good, the electrical panel door switches are good. My homing sensors are good. I'm really wondering if it could be my NC616 card? The one the drives plug into?

and thanks for the reply.

also does anyone know what machine parameter T 51 does?

Mazak "T" parameters are usually timers.

You should be able to use the ladder and follow the E-stop condition to determine what is throwing the alarm.

The E-stop ladder sections are pretty complicated, you just have to work through them one element at a time.

What you do is find each element on the E-stop ladder sections, then check the status of each input/output using the diagnostics monitor on your screen.

Of course you need the ladder to go by, usually have a ladder manual. Some Mazaks you can monitor the ladder on the screen, not sure if T-32 can or not?

ON EDIT: I had a "transformer overheat" one time on a QT, and that kept the machine in E-Stop. It was a bad temp sensor (the transformer wasn't actually overheated), so I just bypassed the switch to get the machine going.

ToolCat

Unfortunately I have everything but the ladder manual. I have ladder manuals for my T-plus machines but I'm guessing the T-32 is different. I had it but a tech years ago, took it home to read it and rolled his truck at which point he lost it. I learned to never allow the manuals to leave the shop. I'll be ordering one from Mazak soon as I believe it would have helped. On the bright side I found the issue.

After pulling the tail stock wires, the coolant pump, removed all the contact switches etc... We checked all the capacitors and resistors on the relay board, swapped out relays etc.... We pulled the cables and checked for continuity on every wire. Unplugged and plugged everything back in after blowing out all the plugs and wiggled them, just in the slightest hope of something happening. After roughly 80 hours of staring at wires and turning the machine on and off, trying to clear the e-stop code, hoping that I didn't see that little red alarm dot light up, I lost my cool and yanked the wires off the cards in the control. I pulled the cards and re installed them one last time. Plugged it all back in and fired it up. E-stop and E-7 lit up on all the drives one more time. I got angry and jammed my hand (more of a punch with my palm ) on the number one card (MC301) on the middle cable. There was a big click, a pop and everything came on, the code cleared. Machine works. I wiggled the board and the code came back on. I put pressure on it and it went away. So I've narrowed it to the connector between the board holder and the card. I'll probably be ordering new ones. For now a couple zip ties screwed to the back wall, strapped over the plugs, putting pressure on the board has me up and running. The frustrating thing is I had a feeling it was at the board. I asked a few techs and they all insisted it was in wiring, not in the control or drives. Technically a plug is wiring I guess. It honestly could have been anywhere. I wonder how many machines have been retired because of this. CNCTOOLCAT I'll be adding the heat sensor to my trouble shooting book. I'm sure I'll have that issue in the future.

Sorry I wrote a novel but I thought it would help other people searching for answers and give a little hope hearing what I went through and maybe add to the E-stop trouble shooting of this Forum. I was about to hook a chain to the machine and drag it out through the wall when it decided to turn back on.