Need Help!- Black screen

[gamila]

Hello all,

I have a VMC20. During a program, the machine spindle stopped and the crt went black. All of the fans will run, the operator light comes on, but no lights on any of the boards in the cabnet are lit. Checked the breakers and reset buttons that I can see, but no luck.

Any help or suggestions on what to check next would be greatly apperciated!

Thank you,
gamila

[Delw]

Just out of curiousity did you chut teh machine down and hit the energize button about the power box? sounds like you had a power disruption and you just need to repower up.


check fuses,
some one posted on here a while back what fuse did what.

[gamila]

Delw

I have restarted the machine many times with the same result. Have checked all the fuses that I can see. Am thinking that maybe there is a bad relay somewhere, but don't know which one to check or swap with another to try.

gamila

[Delw]

I dont think a relay runs the monitor, the power supply does. Besides relays generally don't go out, the will buzz when they are going bad, unless the power supply went out making it so a relay won't come on.
What I do find odd is that the spindle shut down as well as the screen blacking out,usually thats an indication of a power disruption and or a power supply.

Didnt mean to make you feel dumb on the green button deal, but believe It or not I know a few machinest who have tried to figure out why there machines stopped and couldnt get it running again.

[gamila]

Delw,

Sometimes the easiest things are overlooked, so I take no offense at any suggestion!
When the main power is on, the fans power up and the operator light comes on. If I hit the green button, the normal faint click can be heard, but nothing else powers up

gamila

[Delw]

Just out of curiosity after you power up hit the green button goto your control and type in CS

see if it jumps, then turn your spindle (manually) on also try hitting jog button.

reason I ask is if all these work then its just your monitor I would think.
Neal will probally have good answers and correct ones for you tomorrow.
Bubba is pretty bright on these things as well.

[little bubba]

Originally Posted by gamila All of the fans will run, the operator light comes on, but no lights on any of the boards in the cabnet are lit.

Since you have no juice to your boards, after you hit the green button, check all three legs coming in, you may have dropped one, both sides of the fuses and all that crap.

Back to the green button, something that happened to me the other day for the first time. Flipped the big switch and then immediately layed on the green button, NOTHING, waited, layed on it again, nothing, again... etc. Ahhh Crap. Flipped the big switch off, waited for about 30 seconds, flipped it on, waited a bit, hit the green button and TADA!!!! Just something to think about.

Just went out to a machine, shut it down and fired up just the power, you will get all of your fans, the power light on the control, light inside the machine, spindle chiller, but no lights on your boards and nothing on the monitor. This leads to me to believe one thing, your power supply is shot.

The power supply is the one that looks exactly like a computer power supply, because that is exactly what it is. You won't get voltage out of the power supply before hitting the green button, you may want to pull it off and hook it to a standard 110 line and check it.

Now, I'm not sure exactly what the green button does, but I think it shoots juice to the powersupply, and then when the power supply fires up everything stays good, so you may be able to check the voltage going into the power supply with two people. One pushing the button, one checking the 120/110 going into the power supply.

I had one machine that lost 4 power supplies in 3 years and one of the failures was exactly as your talking about. So, now you know or think its the power supply, Fadal wants over $400, CNCpros wants $240, the computer store down the street wants $30 and you can find them online for as low as $5. Of course the power supply in your machine is a non-switching supply and the new ones are switching. Buy the switching supply and jumper the green to grey or green to black(DO A GOOGLE search first, I claim no responsibility). Chop some wires and you are good to go. On the switching supplies there are some voltages you don't need, just tape them off, but the colors are all correct.

One other thing I did, while on the subject of power supplies, is wire in a standard computer power cord to the machine so that there was less cutting and chopping the next time the power supply went out. I'm not sure how common the toasted power supply is, but we had some strange voltage spikes and drops in that shop, the computers ate them like crazy too.

[gamila]

little bubba,

Checked the incoming power, and have tried restarting numerous times.

I am not sure if my machine has a pc power supply (1991). If it does, where is it located? In the main cabnet, mounted near the top is a panel that has a transformer and a board and some other stuff on it.

gamila

[little bubba]

Originally Posted by gamila little bubba, Checked the incoming power, and have tried restarting numerous times. I am not sure if my machine has a pc power supply (1991). If it does, where is it located? In the main cabnet, mounted near the top is a panel that has a transformer and a board and some other stuff on it. gamila

'91? Never messed with one quite that old. But you are probably looking at the right thing, its in the right spot. I'm guessing that it probably is the same thing. What are the outputs on it? I'm guessing you have +12, +5 and a -12v(maybe a -5, its been a while). After the stuff you have already done(which is exactly what you should have done), I'd start there, that's where the juice is coming from to run all of your boards.

[gamila]

little bubba,
The outputs are 5V, 12V & -12V. All are dead, but there is 110V on the board at the 110V fuse. Would it be possible to wire in a pc power supply???

[little bubba]

If your 100% sure that there is no power getting to the supply and nothing is coming out of it, then yes, easy to replace with a computer power supply. Don't worry about the wattage, any new power supply is way more than the Fadal's originally had in them.

Or you can go buy the correct one, which is the same exact thing with chopped wires, just a whole lot more money.

[gamila]

little bubba,
If I push the cnc start button, there is a 12V surge at the +12V line on the power supply board and less than 1V at the +5V line. I believe that this means the power supply is bad. My question is, how and where do you hook the pc supply in? what do you do with all of the wires going into the current power supply?
gamila