[Glen_mar13]

Hello,

I am running a 1985 mazak that has a mazatrol cam t-2 control. It seems to run great in the morning but by lunch it throws a random alarm No. 20 emergency stop. I can not reset this alam out. I have to completely shut down the machine for it to go away. It'll usually do it about once an hour sometimes more after the first time around lunch time. If anyone can help it'll be greatly appreciated.

[neilw20]

Running until warm? Socketed eproms (usually 28 legs and labels and little windows) start to become crook at elevated temperatures.
Eproms with this problem can be read after hitting with a can of 'cold' and then burn a new one (if you can find one of that type).
If you don't understand this bit, leave the repair to experts, but by all means try the cold treatment, provided, opening a cabinet door doesn't defeat you.

Run a COLD air stream past the boards, if you can, and see if it survives past lunchtime.
See WARNING below before unplugging anything.

Re-seat all the PCBs, but this might ADD a problem, WARNING: If you pull one and the backup battery disconnects, that board or others might become a zombie.

Old dirty microswitch? Oil in a switch? Bum connection in ESTOP chain? Give all wires a tug and hope none come off in your hand.
Continuously flexing looms/cables/connectors? They are 28 years old now. Are some strands on there last legs?

Round blob style diodes if there are any? Look first at orientation, give them a flick. Bingo!! gone! The wire bonding at the blob has aged beyond usefulness.

Experience here pre-dates when IC's came into use!!!
The 'old eprom' is a most likely culprit, if wiring/switch problems are not there, and it passes the flick test.

[wizard]

1985 is pretty old so how to respond here is somewhat dependent on the machines service history. If it hasn't been serviced in a long time the first thing to do is an electrical PM.

A basic electrical PM involves tightening every nut bolt and screw in the machine. It is surprising how many intermittent problems just go away after this is done! Connections have a tendency to work loose over time with some components more prone to issues that others. While this is being done all contact blocks relays and Pushbutton mechanisms should be inspected for soundness. Some brands of contact blocks are known for coming loose from the devices they are mounted on. Considering the vintage of the hardware it wouldn't thrust to inspect the inverter drives especially the capacitor arrays. I'm thinking FANUC here but their drives have bus bars connecting the capacitors and if the connections come lose at all you will get erosion of the bus bar.

One thing to consider is plug and socket connections. Thermal cycling and the like eventually impacts the connections. One product I can highly recommend here comes from Home - CAIG Laboratories, Inc.. This is their Deoxit D and Gold series of contact cleaners and enhancers. I once had a machine with a FANUC ROM board that was giving us machine faults, one application and the machine was good for years until we got rid of it.

Part of any good electrical PM requires a check of ventilation systems. In this case fans and filters most likely. Depending upon you power density fan failures can quickly lead to other hardware failures or intermittent hardware.

Hello,

I am running a 1985 mazak that has a mazatrol cam t-2 control. It seems to run great in the morning but by lunch it throws a random alarm No. 20 emergency stop.

More information would help here, I'm not all that familiar with Mazatrol hardware but if you have a manual the definition of Alarm 20 might help. That is is it a general E-Stop or is the error throwing an E-Stop condition. It is a important to understand how the error is suppose to be generated as that can direct your debugging.

I can not reset this alam out. I have to completely shut down the machine for it to go away.

A lot of CNC controllers are like that for some reason. Many faults require you to cycle power to clear. However this might indicate that machine is finding a fault and setting the E-Stop condition.

It'll usually do it about once an hour sometimes more after the first time around lunch time. If anyone can help it'll be greatly appreciated.

I have to agree with the above poster this could be a thermal issue where the machine warms up creating an intermittent issue. More information on error 20 would be very helpful in understanding what is going on. Hopefully a Mazatrol expert can chime in here. It makes a big difference if this error Is indicating an internally generated fault or an actual E-Stop signal was seen.

[mazak-user]

Hi,
if you get the alarm look into the electric cabinet on the the axis servos TRA31 or TRA41. You can see some LED vertical and horizontal. What you can see?
Also look at the FR-SE ... or FR-SX ... spindle controller. You have on the left side vertical 5 LED and a diagram on the cover. What can you see? Send pictures.

Best regards
mazak-user


Gesendet von meinem PAP5000DUO mit Tapatalk

[ifixcnc]

Check the power supply voltages, hot vs cold. Sometimes old PS drift out of spec.

[Glen_mar13]

Thank you everyone for your inputs. Most of this stuff is out of my reach but we have a guy here that is very smart and knows a lot about that stuff so I'll have him check it out. I will follow up with you guys when we figure something out. If need be, I will post pictures. It didn't do it to me all day yesterday but it was also 20 degrees where as the day before was 60 degrees. So the heat makes perfect since to me. Thanks again for everyone's help.

[wizard]

Heat could very well be the issue in and of itself or it could be exposing other issues. This is why one of the first things to look at for these sorts of issues is the cooling equipment or in most cases fans and filters. Considering the age of the machine it wouldn't hurt to buy new fans and throw out the old even if they aren't the root cause of this problem. This especially the case if the fans have never been replaced. In a nutshell fans, like most machines, do not have a infinite life span.

However do realize that the fans might not be an issue here. Normal heating in the electronics can lead to breakdowns that are thermal related. This is often in the form of bad solder joints though there are other things that can happen.

Thank you everyone for your inputs. Most of this stuff is out of my reach but we have a guy here that is very smart and knows a lot about that stuff so I'll have him check it out. I will follow up with you guys when we figure something out. If need be, I will post pictures. It didn't do it to me all day yesterday but it was also 20 degrees where as the day before was 60 degrees. So the heat makes perfect since to me. Thanks again for everyone's help.

That is one cold plant, machining frozen Popsicles are we? I shouldn't talk, I've been getting up to sub zero temperatures to drive into work the last few days.

The follow up would be appreciated.