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

Thanks for the reply and the schematic attachment. Unfortunately I do not have that schematic in my book.
I have attached the schematic my technician was working with and used to explain to me why he thought SB was the problem. I have SB highlighted on the attachment.

What you circled is NO contacts to supply 24 DC to the whole machine, BUT to be able to do it NC needs to send 24 DC to activate this SB relay.

By saying this is clear, even is SB was pulled out of the socket, you still need to have NC running and be done with self diagnostic.

Thanks for the info. All I know is, after 3 hours of poking around with a multimeter and poring over wiring schematics, a hired professional somehow got the machine to power up. He claimed he pulled this SB relay out, checked it, put it back in and the machine powered up. It worked for 5 hours after he left. It started up the next morning and worked for another 3 hours, then it just shut off again with no warning. I checked the SB relay base with a multimeter and found 24V available but pushing the ON button gets no signal to energize the relay.
Communicating with another individual, they suggested perhaps there's an issue with a 5V power supply that provides power to the buttons on the front panel letting them release unexpectedly ? I was told the 5V power supply may be similar in size to the 24V unit, but have yet to locate anything like that. Anyway, today is another day.....

cause it happened to me as well ( ages ago) , I pushed one of those relays out of its socket and couldn't understand why machine wont start, until I found the problem.

Your power supply for the NC rack could be going out. It is a large, dark brown "rectangle" to the left of all the NC cards. It outputs multiple DC voltages.

The symptoms you're having would indicate a failing power supply. You can source a spare or two to try on Ebay.

You might also try (with the machine off), unplugging and re-plugging all the NC cards, and the connections to them.

Good luck with it!

ToolCat

hard to understand your situation. What is happening now? Swap SB relay with any other relay around ( same type ) to eliminate failing component issue

handsonman said:

Communicating with another individual, they suggested perhaps there's an issue with a 5V power supply that provides power to the buttons on the front panel letting them release unexpectedly ? I was told the 5V power supply may be similar in size to the 24V unit, but have yet to locate anything like that. Anyway, today is another day.....

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On two of my T-3 controllers, there is a 5V power supply behind the control keyboard panel itself. Open the door to expose the CRT and there is a 5V, 2A power supply mounted below the CRT on some models. Mine was dead and all of the red LEDs on the front panel were also dead.

I sourced a 120v to 5VDC, 2A power supply from an old camera charger I found at Goodwill and wired it in and the machine came back to life. It's been in there for 9 years now and still works. Lol.

In reply to CNCToolCat ... I believe you're referring to the PD14C-1 unit ? With the ON button held in, it will show every voltage EXCEPT 24V. I had purchesed a second unit from eBay to try, but it acted the same way.
My friend has a similar vintage MAZAK and allowed me to plug my power supplies into his machine to test them. BOTH power supplies worked in his machine, so I had to rule them out based on my testing.
I also tried re-inserting the NC cards as well as swapping them for others in my collection, in hopes that something would make a difference. NADA

Replying to noname777...... I had traded relays from other locations with no change.
And I agree, it is hard to understand..why fiddling with the relay made it come on for a several hours than mysteriously wink off again for no apparent reason. No alarms, no nothing. Like someone just turned the power off; which in essence is what's happening.

Replying to Philabuster...... Thanks for the repair idea. I like the way you think.
Necessity is the mother of invention and desperation is the father. LOL
Speaking of desperation, I ordered a replacement front panel complete with PCBs to try.
It should arrive today...

ROUND -2
Same service guy came in today and started poking around and making phone calls.
After a couple of hours he comes to me and says my electrical handbook isn't for my machine.
I knew that and thought he did too 'cause he had looked at it last week.. But it's what came with my machine and the control version was the same.
But I understand there are or could be subtle differences between different sized machines.
So, he has me call MAZAK to request a copy of the wiring schematic for my machine.
I call the number he gives me and turns out they don't service my area so I have to call again up to New England.
I give THAT guy my machine number and he says it's not registered to me . WTF ?
I say I've had this machine since 2008 and I know I registered it years ago, cause I bought stuff from them.
He pokes around and says- oh yeah, you did buy from us but we updated our system (or some s--t) and now I'm not registered anymore and have to re-register.
They send me a form to fill out and send back.
At some point, I hope before New Years.. they will re-register me so I can buy a copy of the electrical manual.
And BTW, they only sell a complete manual not just what you need.
Good news is, I can buy a hardcopy @ $150, a CD @ $125, or a PDF download @ $100
I'll take the pidiff as it's cheapest and fastest to get...AFTER I'm re-registered that is...

In the meantime the service guy runs out of options so starts swapping out circuit boards, just like I did last week (with no success). Presto, he gets the machine going again and proclaims my original FX773 board had a short in it.
I only had one extra FX773 board; so how's come it's working now and didn't last week when I swapped it ??
I signed off on the service guy's work and he joked he doesn't want to see me again. The feeling's mutual Bud ..
Anyways, the machine is working ...again. But I don't trust it. That was too easy. Same as the SB relay thing.
One thing the service guy said before he switched out the board was, that maybe the card rack circuit board has damage or a loose connection. I found a cheap replacement on ebay complete with another power supply , which should arrive in a couple of days.. I hope I don't need to mess with it.

I dont like it, what does FX773 board do? Is it I/O interface board? IT might be some proxy or valve is playing up, or cable connections towards proxy switch

Even though the electrical manual you have is not specifically for your machine, I bet a dollar to doughnuts that it's the same as the one you're buying. All those QT15's pretty much have the same electrical schematics, with the only difference being the control (T2, T32, T-Plus).

The FX773 is one of the memory boards for the T2 control---I think it contains the PLC programming (not sure), but it is definitely an important board! (Along with the FX784-8 and FX784-9, or single FX884).
So you may have gotten a break, swapping out the FX773 and getting her going!

Cheap spare parts via Ebay is your friend...

ToolCat

doesnt look like memory. does it? it has SSR units on it. So probably, electrician was just shaking cables or got away with replacing IO interface board.

Reply to ToolCat- I agree, a T2 is a T2 . The basics "should" be the same regardless of machine.
But to be fair, my manual was for a QT8; which I believe has the components rearranged differently on the machine.
Of course, that would require different wire routing.
But looking through the manual, whatever machine it WAS for, used the same boards as my QT15.
And yes, eBay is MY FRIEND. I've bought all my spare boards from there, with many having return privileges.
Way cheaper and faster than sending out a board to be tested/repaired.
Which brings up another point- the service guy was telling me I probably couldn't get my boards repaired anymore because they're too old. Really ? The FX773 board that was pulled had a Nu-Tek repair sticker on it. Go figure.

Reply to noname777- I'm thinking the same thing- all that poking prodding and jiggling got a weak connection back online. The machine started up this AM and is running fine. I still don't trust it, but will let sleeping dogs lay.

ROUND- 3
New week, new alarm
So the machine worked flawlessly all day Friday.
I power the control down on Friday but left main power on. No work this weekend because of Holiday.
Today, Monday, I turn machine control on and what do I see ? NMI-20 alarm and no hydraulic pump sounds.
WTF now ???
Go in the back and check the various power supply voltages.. surprise, I have everything at the power supply even the elusive 24V
Check for any tripped breakers or blown fuses. Nothing
Out of curiosity and desperation I decide to turn the power off and on at the PD14C-1 power supply buttons.
Two times doing this and......Bam, the machine powers up.
So what is THIS telling me ? Still seems like a shaky connection somewhere. Maybe the unusual cold weather ?
It's on now, so I'm not messing with it anymore unless I have to !

Sounds like your PD14C-1 power supply (PS) is going bad. Either swap it out, or replace all the capacitors onboard (a big job!)

Failing power supplies are infamous for not powering-up initially, but eventually working after warming up.

It's not always the actual DC voltages that will measure out of range on a failing PS, but something called "AC ripple" can degrade the quality of the DC voltages to the point the components powered by the PS will not work.

Increasing AC ripple of the DC voltages output by a PS is due to the increasing of the "ESR" (electro-static-resistance) of the internal capacitors as they age.

ToolCat

You know what Mark Twain said once?

It ain't what you don't know that gets you into trouble. It's what you know for sure that just ain't so

You are focusing too much on your power supply board.
Alarm NMI-20? What was the status of all possible LEDs on your control?

Happy New Year.
Just a quick follow up to this power situation.. I decided to just leave the machine turned on with the monitor turned off to save the screen. I have too much work piling up and can't afford to keep messing with it.
So far so good.
Actually, I had to turn it off to make an adjustment to the central turret tension nut 'cause the turret started over shooting it's positions. But THAT'S a story I'll leave for another time.
But at any rate, the machine came back on more than once with no problems.
Now, to play catch up.
Hope everybody is keeping busy !

handsonman said:

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

Click to expand...

Is this you Mr. Hostetter??? Sounds like you

handsonman said:

Happy New Year.
Just a quick follow up to this power situation.. I decided to just leave the machine turned on with the monitor turned off to save the screen. I have too much work piling up and can't afford to keep messing with it.
So far so good.
Actually, I had to turn it off to make an adjustment to the central turret tension nut 'cause the turret started over shooting it's positions. But THAT'S a story I'll leave for another time.
But at any rate, the machine came back on more than once with no problems.
Now, to play catch up.
Hope everybody is keeping busy !

Click to expand...

Ok I am sure it is you now