What's new
What's new

Mazak QT10 T Plus - in a coma

trencherfield

Plastic
Joined
Oct 17, 2020
Hi everyone,

Been stuck for probably eleven months or more trying to fix this particular machine. We've had it for decades. One day last year it stopped and froze (so I was told) then turned off then on again and screen remains blank. Screen is on though, you can see it fire up/off okay.

Best to say what I have tried so far;

1) Checked batt - ok 3v no alarm for that.
2) Checked the QX084 power supply - green led on, so checked all voltages : 5v=4.98v, 12v=12.1v, -12v=-12.14v, 24v=24.15v observed steady figures, no fluctuation - within Meldas specs on pdf.
3) Replaced QX141 with ebay item - no change.
4) Replaced Qx722 daughterboard - no change.

Current leds;
Power supply green as stated.
Qx141 both green.
Qx722 one green one red.

Tried booting with other 2 cards pulled, no change.

Hydraulics not starting up and only 000 000 on control leds lights up.

Checked volts at the two big contactors - one on left has 3 phase ok at top but not coming out, one next to it is also 0v top & bottom of it.

So, after doing all that, just stumped. I refitted the original Qx141 tonight with the new ebay Qx722 as an alternate combo - same outcome, qx141 leds are green so assume that's okay. Just one red on the 722 and one green. Solid not flashing.

Seems as though a relay is not latching somewhere .... I have no idea now.

Any pointers... I have some pictures I took tonight I can probably upload tomorrow.

Oh the 3 big cream coloured boxes on the right (spindle drive? + power supply etc) have a little square led display that says 'A4' on two of them and '6' or maybe 'b' on the power supply one. Is that normal?

Regards,
Neil.

edit: Forgot to add also checked the 4 smps seperate, two 5vdc units both 5.1vdc, two 24v units both 24vdc bang on. I've run out of things to poke my meter on ha ha :crazy:
 
Last edited:
The tiny square surface-mount capacitors can go bad on the main CPU board, the QX141.

I learned (the hard way) that when changing out a bad QX141, you have to pull a couple of microchips and use on your new QX141...along with the memory cartridges.

Seems like you have to remove the daughter board to access the chip(s) needed to pull.

Can check my notes on Monday...

But overall, when a T/M+ machine just won't work, you have to confidently rule out the QX141....

ON EDIT: You have to re-initialize the control after swapping QX141 as well. (MEAU or Mazak has the procedure).

ToolCat
 
The tiny square surface-mount capacitors can go bad on the main CPU board, the QX141.

I learned (the hard way) that when changing out a bad QX141, you have to pull a couple of microchips and use on your new QX141...along with the memory cartridges.

Seems like you have to remove the daughter board to access the chip(s) needed to pull.

Can check my notes on Monday...

But overall, when a T/M+ machine just won't work, you have to confidently rule out the QX141....

ON EDIT: You have to re-initialize the control after swapping QX141 as well. (MEAU or Mazak has the procedure).

ToolCat

Thanks for the reply. Appreciated.
Yep, I've done that when trying the QX141 replacement (changed the two socketed chips over).
Same result, board gives 2 green led, so both are indicating they are okay. It's the smaller QX722 daughterboard with the one red led, the other green.

Changed that too, then changed it again on the other qx141 for good measure.
Same result. Hence the frustration and 11 months.... I walked away from it before I lost my temper alltogether. My brother is fed up with it as well and Mazak uk don't want to know.

We are up north and not placed in a good area for techs either.

Yes, I have the initialise proceedure too, but cant get anywhere with that either as the machine simply will not start up enough to do anything with it.

I have a gut feeling it's a power/relay issue. Should there not be power past the first main contactor?

Neil.
 
Should there not be power past the first main contactor?

Yes.

You have to make sure you've got power everywhere you're supposed to.

Sometimes an ice-cube relay on the main circuit-board panel can go bad, and I've even seen the small black "solid state" relays go bad.

There are several relays on the main CB panel that have to turn on, in order for the machine to turn on. One in particular is "NC Ready", or "E-stop"...or similar. (Study your electrical manual...)

I have also seen a bad trace in the main CB panel take a machine down. (Can wire around a bad trace, as long as you can find it!)

ToolCat
 
Imgur: The magic of the Internet

Stack of pictures on above link from Friday night at 4am :ill: (desperation lol)
Thought some good pictures are always a help.

So the big contactor 'KM21' in pic has 3 phase going in at the top - nothing out the bottom. Identical unit 'KM1' to the right has 0v top & bottom.

GNQ4uXQ.jpg


Brother said there was an 'E-stop' alarm at some point in days preceeding IIRC so that rings a bell.

General layout...

EhP2VOz.jpg


yvHcTYs.jpg


JgmjsZD.jpg


iIl0Afg.jpg


Are these the ice cube relays to check? Or others somewhere else?

ti1gN3z.jpg


Other board behind...
i2C19sR.jpg


CP
R5oVSAO.jpg


Oh dear, have to start digging for the manuals then in what can only be described as an absolute mess of filing cabinets :scratchchin:
 
Oh yeah, I swapped out KM21 previously with the one from our working QT10 Fusion - but still the same, so put the original back as it was. Just remembered what I've tried.
 
Can anyone give me an idea which relays to check & swap to try? A rough location where they are or next to would be great.

Not been able to locate the electrical manual for this, not being used or on top the machine it's slipped into the abyss of mess somewhere, if we even had one.
 
If KM21 is the first contactor after the incoming supply to the machine and you want to find out what should bring it on, without the drawings, you need to trace the wiring from the coil connections (A1/A2) - go back from here to work out which relay or supply you are missing.

If it is the main control on contactor then I would think you have an e-stop fault as you suggested.

One of your safety relays has a supply onto it, but neither channel is made. Trouble is, the e-stop circuit will probably also include an NC ready signal, so if you have an NC problem, you'll have an e-stop problem.

One of our sites has a couple of QT15's with T2 control, slim chance the e-stop/control on circuit could be similar to your control - I will dig the drawings out when I am next on site later this week.

Will Mazak UK not supply you with replacement drawings?
 
Might be a silly question but have you checked all the 24v power supplies in the machine? Longshot but if one of them is bad it could stop relays working.

Hi, thanks for the reply. Yes checked all four SMPS including the two 24v ones - see bottom of my first post at top.
Cheers.
 
If KM21 is the first contactor after the incoming supply to the machine and you want to find out what should bring it on, without the drawings, you need to trace the wiring from the coil connections (A1/A2) - go back from here to work out which relay or supply you are missing.

If it is the main control on contactor then I would think you have an e-stop fault as you suggested.

One of your safety relays has a supply onto it, but neither channel is made. Trouble is, the e-stop circuit will probably also include an NC ready signal, so if you have an NC problem, you'll have an e-stop problem.

One of our sites has a couple of QT15's with T2 control, slim chance the e-stop/control on circuit could be similar to your control - I will dig the drawings out when I am next on site later this week.

Will Mazak UK not supply you with replacement drawings?

Right, thanks for the reply. So it's often very hard to diagnose the e-stop problem because it could be a relay or not as the NC ready can cause it either way.
All of the drives are ready, awaiting the ready signal from the NC too according to the Mitsu pdf.

Looks like I'm not going to get anywhere with it really. Probably it's days are numbered.
Business is not great given current climate either, so can't spend on it any more.
Our experience with mazaks over the years has been poor. While the big old Hitachi 25S cnc out the back is built like a tank! All I've had to do to it is rip out the old crt & fit an LCD to it using a video converter.
 








 
Back
Top