NEED HELP- QT-15/CAM-2 won't power up completely

I recently had a situation where my 3PH power supply had an arc happen at the bus bar/circuit breaker connection when I turned on the main power switch on my QT-15 /CAM-2. I cleaned the breaker connections and moved the breaker to a new spot on the bus bar. I checked the line voltage, and it seems to be adequate.
But now the machine won't power up completely. Turning the main switch ON will power up the cabinet cooling fans and the spindle and servo drives; which are displaying codes. Spindle drive shows an E7 which is an alarm of some sort.
So, SOME power is getting through as it should.
Now when I press the control start button, I hear a contactor click but the hydraulics don't power up and the monitor won't come on completely.
If I hold the start button in, the monitor will light up with only a black and white static image but will not stay on if I take my finger off the button.
I have an electrical manual for the machine, but it doesn't really explain the sequence of events upon start up.
I have checked the 3 automotive fuses below the spindle drive and they are OK and also checked for any other tripped breakers or blown fuses and found nothing obviously tripped or blown.
It seems to me, there's a contactor that needs energized to allow power to flow through other parts of the system upon start up.
Like I said, I can hear a contactor "click" but nothing powers up. So the power is being held up somewhere by something.
If anyone has had similar experiences and could advise some items to check or how to remedy this situation, I would greatly appreciate it. I have a call into a local service tech, but have no idea when they will have time to check my machine out. And of course, work is backing up.
TIA

somewhere on the NC rack you should see a sticker that says what Mitsubishi NC control it is. Take a picture and upload it here

noname777 said:

somewhere on the NC rack you should see a sticker that says what Mitsubishi NC control it is. Take a picture and upload it here

Click to expand...

Hi Noname777, I have a attached a photo of the NC rack. Regarding ID stickers, not too much to go on I'm afraid..

noname777 said:

somewhere on the NC rack you should see a sticker that says what Mitsubishi NC control it is. Take a picture and upload it here

Click to expand...

It's a T-2 control.

Yes,thanks. I believe that's correct.

OK, doing a little more digging.... I found a troubleshooting reference mentioning exactly what my machine is doing. The machine will come on (sort of) but doesn't stay on. The guide said to check the PD14C-1 power supply for voltage. Checking the set of pins near the top with a multimeter showed we had all voltages EXCEPT +24V.
So I'm suspecting the power supply has a short in it. 24V is probably the voltage used to activate the relays, which would explain why nothing is powering up ?

no, there must be another label with MITSUBISHI NC model number, T2 is Mazaks coding name, Mitsubishi uses different names, something similar to attached picture. Is there anything like it? like MELDAS YL-D???

I found it !

Here is where I am at with this today... I found a used, supposedly pulled from a working machine, PD14C-1 power supply unit w/30 day return privileges and installed it. Same damn thing- NO +24 Volts. Everything else has the appropriate voltages at the test pins. Do I have a second defective unit or is something else going on ??? I contacted the seller of the unit who is a CNC repair shop/ parts reseller and waiting to hear back.

Follow up to the PD14C-1 function question I previously posted... I found out my friend had a Mazak with a T3 control and the same power supply. He was kind enough to allow me to test my power supply in his machine and wouldn't you know ... it worked. So, back to square one. I'm wondering whether one of the FX boards is tied in with this situation.

-Where is your P24 ( inside electrical cabinet coming from ) coming from? Its it coming from the same PD14C-1 or there is another source of +24DC.
-Power up your machine and start pulling out of the rack one by one all your PCB boards to see the difference.
-What about DC voltage distributer? Start disconnecting all recipients of P24 till it is back to normal.

Good question. Seems like the 24V must be coming through from somewhere else, so will try tracing that today.
But, I can only power up by turning on the main switch, I can't actually get the control to come on. Probably for the lack of 24V. Not familiar with the term DC voltage distributor.

Follow up- I located a 24V power supply on cabinet door- LAMBDA LSS 37-24.
It's putting out 24V, so I can cross that off.

well, than start pulling NC boards, may be one of DI or DOUT channels is shorted.

The 24V DC circuit is critical, as it creates the necessary "machine ready" indications.

Trace the 24V DC to the main circuit board: one or more relays in the circuit have to stay ON for the machine to be in the ready state.

You could have a bad relay (most are plug-in, ice-cube style), so that is an easy swap and try.

The power glitch you had may have burnt a trace somewhere on the 24V circuit.

Although difficult to interpret at first, a thorough study of the electrical manual can help you decipher the "machine ready" circuit...

Good luck with it,

ToolCat

handsonman said:

OK, doing a little more digging.... I found a troubleshooting reference mentioning exactly what my machine is doing. The machine will come on (sort of) but doesn't stay on. The guide said to check the PD14C-1 power supply for voltage. Checking the set of pins near the top with a multimeter showed we had all voltages EXCEPT +24V.
So I'm suspecting the power supply has a short in it. 24V is probably the voltage used to activate the relays, which would explain why nothing is powering up ?

Click to expand...

most units need the 24V first to power up all the safety circuits and communication and allow the machine to communicate that it is ok to start up and close the main contactor to power the dc buss on the drives.
you will need to pull the power supply and check all the circuits inside of it. there can me micro transistors, capacitors and even resistors that can be a culprit. had mine repaired here for a few hundred bucks and it was 2 resistors the size of a ball point pen tip that went bad and only had half the 24V and half the 5V.
find an industrial electronics guy that knows these units.
just because it outputs 24V doen't mean it always has enough amps.
other times circuits will short that it feeds into, pull the wiring and see if it comes back up to 24V.

Good news- Machine is going again, and thank God it was a simple (but tedious to find) fix.
After a lot of wire tracing via schematics, we found that the SB relay on the door panel had apparently developed a poor connection in the socket. It wasn't accidentally bumped out of place or anything, as it had a metal clip holding it in. Relay was pulled for inspection, reinstalled, and presto..the machine powered up. Weird.
Will definitely record this in my troubleshooting notes. Thanks for everyone's help with this.

Follow up to previous post...
#%$^&@!!!! machine winked out on me again
It was turned on all afternoon yesterday and about 2 hours this AM.
Was setting up a job when...bink,,,same dang thing....like I hit the stop button.
I swapped out the relay with another, but it made no difference.
Back to square one.

doesn't make any sense. SB relay is activated by NC. Once NC is loaded and self diagnostic is done, it should energize it. Correct? And in your case NC was completely OFF, no signs of anything at all.