Fanuc 3TC problems

[roni21702]

When I started my lathe today with a Fanuc 3TC control it started as normal but shortly after the axis took off and the CRT went blank. I shut down and started back up the same thing happened again. After a few times of this now the CRT does not come up so I don't know what is going on. I can't get the machine to do anything. I was wondering what would happen if the memory batteries went dead between uses? Anyone have any ideas for me. Thank you for your time and hope to hear from someone soon.

[Dan Fritz]

I doubt that it's a dead battery. The Fanuc 3 would have given you a battery alarm long before it went dead.

Whenever two or more things happen at the same time like this, it's likely that there is a common cause. The first thing I would do is pull the fuses on the servos (so they can't run away), power up the control, and thouroughly test the power supply. If this is a slant-bed lathe, you may want to block the cross-slide so it doesn't drift down when you power up with no fuses.

Your power supply should have stable output voltages of +5v, +24v, and also +15 and -15v. A blown voltage regulator or a short somewhere that's affecting the power supply could cause a problem with the CRT and with a servo at the same time.

Also check the connectors on the cables from the power supply to each board. Look for any discoloration on the connectors that could indicate that it's been getting hot. If any board starts to loose power from a bad cable connection, all kinds of unpredictable things can happen.

[roni21702]

I have been testing the power supply and I found out that the power supply does not have any input voltage. Does anyone know anything about a Leblond Makino lathe made by Gildemeister? I am looking for any help thank you

[gilchapa]

I once had that problem and it turned out to be the relay that fed the power supply board. The guildemeister lathe that I have has a relay array that has to meet certain conditions in order to turn on the NC. Check the end limit switches and the main fuses.