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Fanuc 0t CRT not powering on

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Plastic
Joined
Jul 28, 2021
I have a Takisawa TC 1 Fanuc 0T control I believe they told me it is a 1986. tried to start it up one morning and when I press the power button the CRT flashes a green dot and makes a strange sound but will not power up the machine. I thought the CRT burn't out so I traded it with a refurbished one but it's still not turning on. There's a red alarm light that flashes when the power button is pushed. It's an old machine and the manuals aren't any help. Does anyone know what causes this? The picture of the alarm light I the board thats on the back door of the machine.
I'm new on this forum and not really sure how to post videos. I'd really appreciate any help that I can get. I don't want to pay a mechanic for them to charge me and tell me it's not fixable.
 

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Check for blown fuses. I haven't had this exact issue before, but with my Fanucs, often the red light on a supply like that can indicate a blown fuse.
 
I always start by checking output on the power supply.

If this is a machine you just had installed; also check to make sure all boards and plugs are seated all the way. When machines get moved (especially old ones) the ride often shakes things loose creating random bad connections.
 
Check for blown fuses. I haven't had this exact issue before, but with my Fanucs, often the red light on a supply like that can indicate a blown fuse.
When you say blown fuse, do you mean a fuse that welded to the electronic board? or a fuse can can be pulled out and replaced? I'm fairly new doing this. I'm a program and operator and I'm really tired of these mechanics charging me an arm and a leg for something that takes them 5 minutes fix.
 
I always start by checking output on the power supply.

If this is a machine you just had installed; also check to make sure all boards and plugs are seated all the way. When machines get moved (especially old ones) the ride often shakes things loose creating random bad connections.
This machine has been in the same spot for 5 years. I just had the spindle bearings replaced less than a year ago. I will check the power supply and try to go from there.

Here are the videos that I have of the issues it's having.
 
I'm fairly new doing this. I'm a program and operator and I'm really tired of these mechanics charging me an arm and a leg for something that takes them 5 minutes fix.

Really gives you a helpless feeling doesn't it? I hate trying to diagnose electrical issues for that very reason. A lot of the inexperienced service techs will just swap parts until something works... Or kills the "new" used part that you just gave a kidney and testicle to obtain.

I'm ok at diagnosing a faulty power supply, bad grounds or wiring shorts, But if it comes down to circuit level, I'm about useless.

Hopefully one of the Fanuc wizards will be along soon to help out.
 
The pulsing alarm light with clicking is new to me, could be a bad or loose relay (pure speculation, one of the more experienced guys might be able to help more). The fuses I am speaking of are replaceable, I would start by checking the Power Supply Unit. Make sure you have proper 3 phase power coming in and full 24 volt power.
 
Was the machine running OK, previously?
Could be a graphics board, power supply, or any number of connections.
Check for blown fuses and popped breakers in the back cabinet.
Also, check the motherboard and see if there's an LED alarm code displayed on it.
 
………I'm a program and operator and I'm really tired of these mechanics charging me an arm and a leg for something that takes them 5 minutes fix.
So you prefer to have a down machine for several days instead?

I did field service for nearly 10 years. Customers that did not value and appreciate my ability and experience to quickly get them running again often would get ignored the next time they were in a jam.
 
I believe Sir it's time to call the mechanic........from your comments it appears you don't know how to find the problem.
This is not the time to be poking around and screw something up and make the problem worse, or even unfixable if you short a board .
No shame in calling someone in.
Now if you're a hobby guy and not really making money then yea it's going to hurt spending the bucks, but I don't see you have any other options.
 
The pulsing alarm light with clicking is new to me, could be a bad or loose relay (pure speculation, one of the more experienced guys might be able to help more). The fuses I am speaking of are replaceable, I would start by checking the Power Supply Unit. Make sure you have proper 3 phase power coming in and full 24 volt power.
It was the power supply unit. Figured out how to read voltages from youtube and the power supply unit was the only one that wasn't reading correctly. Bought a refurbished one from ebay for $150, plugged it in and now I'm up and running again. Thank you!
 
So you prefer to have a down machine for several days instead?

I did field service for nearly 10 years. Customers that did not value and appreciate my ability and experience to quickly get them running again often would get ignored the next time they were in a jam.
I appreciate techs and their knowledge but I have have terrible experiences with multiple ones in my area who have cost me over 5K for different issues and never fixed the problems I had. It's not a machine that is constantly running so it wasn't a big deal to have it down for a while.
 
I appreciate techs and their knowledge but I have have terrible experiences with multiple ones in my area who have cost me over 5K for different issues and never fixed the problems I had. It's not a machine that is constantly running so it wasn't a big deal to have it down for a while.
So a tech bills you while not fixing the problem and then you pay it? Machine would have to be fixed before I would pay any bills.
 
All power supplies do is convert AC current to low-voltage DC, yet they're one of the most common failure points on older cnc machines.

Often when a PS starts failing, you will begin to have trouble getting the machine to power up completely. Usually it eventually will, and you keep on machining.

Until one day the 'ol girl just won't power up. Check the PS's first!

ToolCat
 
All power supplies do is convert AC current to low-voltage DC, yet they're one of the most common failure points on older cnc machines.

Often when a PS starts failing, you will begin to have trouble getting the machine to power up completely. Usually it eventually will, and you keep on machining.

Until one day the 'ol girl just won't power up. Check the PS's first!

ToolCat
That's great advice and definitely useful! Thank you
 








 
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