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T2 Control power on issue

bda9865

Plastic
Joined
Dec 22, 2011
Location
louisiana, usa
Hi All,
I own a 1986 QT10 with a T2 control. My problem is sometimes when I press the power on button the machine won't turn on at the control.The fans come on and that's it. This problem is very sporadic The machine may work fine for 3 or 4 days as in the control powers up the machine no problem and then it begins to have the control issue again. So far I've been able to get the machine to work with the control issues and once the machine is working it will run all day without any issue. I can even turn off the machine at the control and it always powers back up. When the problem does occur it primarily seems to happen on initial start up in the morning after it's sat through the night. Has anyone ever had this problem? Thanks in advance for any help.
 
Hi All,
I own a 1986 QT10 with a T2 control. My problem is sometimes when I press the power on button the machine won't turn on at the control.The fans come on and that's it. This problem is very sporadic The machine may work fine for 3 or 4 days as in the control powers up the machine no problem and then it begins to have the control issue again. So far I've been able to get the machine to work with the control issues and once the machine is working it will run all day without any issue. I can even turn off the machine at the control and it always powers back up. When the problem does occur it primarily seems to happen on initial start up in the morning after it's sat through the night. Has anyone ever had this problem? Thanks in advance for any help.

When I first got my machine (same model & year as yours) I had that problem. If the machine isn't used for a while, that problem will show up. I think it's due to a set of dirty contacts in a small power-relay, but I haven't troubleshot the circuit.

When you have this issue, do you hear a relay click when you push the power-on button?

There is a tiny relay in the Mitsubishi control box (I believe it's on one of the FX boards).
You need a second pair of hands to trace the circuit down; someone to push that button while you use the DMM.
That's what has stopped me from investigating farther.
 
On the power supply for the CNC is a switch that allows you to turn it on from the back of the machine.

When you have pushed the power on button, are the lights on the circuit boards in the chassis the same as when it does not power up?

The module at the top of the FR-SE Spindle controller has a LED that can be seen through the air vents.
Is it lit when it does not power up?

Once there are answers to these questions, we can guide you further.

Bill
 
I don't have that particular machine, and I don't recall having that particular problem (on a Mazak)..

I HAVE had that problem on a Fadal.. And it was f'd up voltages from the power supply.. 11.87V and
she would fire... 11.85V and she wouldn't..

Anyways I would start hitting the low hanging fruit. Checking voltages and pop the back off
the transformer and tighten stuff up.

Nothing is worse than digging deep into a problem, and the actual problem turns out to be the first
thing you SHOULD have checked, but didn't, because it could never be that.
 
when the control works as it should I hear the relays click and the machine powers up. When the control doesn't work the relays don't click in. Thanks for the information on the small power relay I'll see if I can find it.
 
Hey Bill,
When the control isn't working I have pressed the power on button on the power supply in the back of the machine and the red light comes on the power supply and the circuit board lights come on as well as the fans beneath the boards. when I let go of the button all of the lights as well as the fans quit working. Concerning the module on top of the Spindle controller the LED is on even when the control is not. It's as if something is keeping the cnc power supply from working. Thanks for looking at my problem
Brandon
 
That's a good point about the voltage. I'll go check today. I have a 24VDC power supply that feeds the G2A and LY2 ice cube relays amongst other areas of the machine. I guess the main question is what would be considered "bad" voltage? I'll let y'all know what I find out
Brandon
 
Hey everybody,
Today the machine started right up no problem ,which is about right when I need it not to work it works!! I checked the AC/DC voltage anyway and my 24 volt DC power supply is measuring 24.2 volts and the 100 AC computer power supply(PD14C-1) measures 101.7 AC going in and 101.6 going out to the control panel which measures 101.5 AC. Although I'm not an electrician I would think that the power supplies are working properly. Any thoughts?
Brandon
 
Hey everybody,
Today the machine started right up no problem ,which is about right when I need it not to work it works!! I checked the AC/DC voltage anyway and my 24 volt DC power supply is measuring 24.2 volts and the 100 AC computer power supply(PD14C-1) measures 101.7 AC going in and 101.6 going out to the control panel which measures 101.5 AC. Although I'm not an electrician I would think that the power supplies are working properly. Any thoughts?
Brandon

You're within 2% on that 100V supply and 1% on the 24v supply, my gut feeling and electronics experience says that's pretty good, but I don't know what the Mazak/Mitsubishi tolerance allows there. Might say the tolerance in the electrical manual somewhere.
 
Random power-on issues tend to be power supply related, as the capacitors in the power supplies tend to fail after a couple of decades.

Make sure the yellow LED comes on every time on the spindle drive. That power supply is a common failure point.

Also, an intermittent short in the 24v dc circuits can cause power-on issues.

One trick to get by for a while is to power-up the main machine breaker, but do not power-up the control for a few minutes - give the capacitors time to warm up and start to function correctly.

Good luck with it, and keep us posted.

ToolCat
 
Thanks ToolCat for the information I'll try doing that with the main breaker and see what happens. Been real busy with other stuff today haven't had time to work on the machine. It'll be tomorrow morning before I can I'll let y'all know what happens. And cwtoyota I do have the electrical manual for the machine I'll take a look
Brandon
 
Hi Everybody,
I hope y'all are still there. I didn't realize it's been almost a week since my last post. Anyway here is the latest it's been a real frustrating week Machine is still having the same problem. Toolcat I tried your suggestion last Saturday of letting the machine "warm up" before I hit the power on button and it didn't seem to work.I let the machine sit with the power on at the main breaker for 30 minutes and it still didn't power up when I pushed the power on button. At this point I flipped the breaker off and then right back on pressed the power on button control didn't come on but I heard a faint click which turned out to be coming from the pd14c power supply. cwtoyota could this be the click you heard on your machine? At this point I pressed the power on at the power supply and the fans beneath the boards came on but no lights on the boards or the red indicator light on the power supply came on. I checked the voltage at this time and I had 100vac going to the power supply but nothing going out unless I pressed the power on button at the power supply and then I had 100vac going out as well let the button go and nothing going out. I turned the machine off and pulled the power supply out of the machine and took the cover off to see I saw anything out of the ordinary like a bad fuse or bulging capacitor but everything looked good. I checked the fuse and it was good as well. I decided what the hell I put the power supply back in the machine flipped the main breaker on and the damn thing powered up at the control with no problem!!! Since it was up and running I checked the voltage at the power supply check points(?) and this is what I got +5v=5.00, +12v=12.04, -12v=-12.02, +24v=24.00. everything where it should be. Machine ran great all day this all happened last Saturday. Monday morning machine wouldn't start at the control again. I went straight to the PD14C powersupply and pushed the power on button and the machine came on as if I had turned it on at the control panel. That's the first time that's ever happened . Machine ran great all day. This past Wednesday same crap different day wouldn't come on, I repeated my procedure I did Monday by pushing the power on button at the power supply and not only did it not come on it was doing the same thing it did the previous Saturday morning before I pulled it out of the machine. Needless to say I was pretty aggravated with the whole situation by then so I flipped the machine and breaker off and worked on other things in the shop. Bear with me we are almost to the end of this superlong post. After I thought about it awhile I decided to try something different on the startup of the machine just to see if it worked. I started to flip the main breaker off and then right back on if the machine wouldn't power up at the control and for the first time since the problem started I noticed a pattern. First flip off/on nothing control wouldn't power up. Second flip off/on click at the power supply but no turn on at the control, Third flip off/on this is where it gets weird the monitor would come on ( the monitor spec screen not the actual mazak control screen) and the Rapid ,spindle and feed led's came on as I pressed the power up button and I also found out I had 100vac at the control as long as I kept pressing the power on button as soon as I let go everything quit working. It was if it was getting partial power. Fourth flip off/on of the main breaker press power on and the machine starts up. I've managed to get this pattern to repeat a couple of times. I know this isn't good for the machine but I'm looking for consistency somewhere to start to trace the problem. Maybe it's coincidence maybe not I'll admit I'm reaching now. BobW I think I'm going to take another look at the transformer . Maybe I missed a power feed that goes into the cabinet that's not working. Maybe it's a bad board FX702 and FX727 are the boards that control the control panel.I would really appreciate any comments/thoughts y'all have. I also forgot to mention that I called a Mazak Tech who's been working on mazaks for years to come by and look at the machine. He was very nice and helpful over the phone but he let me know that he didn't work on that vintage of Mazaks. I was afraid of that. Finally I do apologize for such a long post and maybe some of the information clutters the post however it's my intent to get as much information out as I can in hopes that somebody can point me in the right direction
Thanks
Brandon
Thanks
Brandon
 
You should be focused on what else is not working properly beyond "it won't power up".
The won't power up is the effect of something else not working properly!

Since you are the operator and the maintenance you MUST switch hats to maint. every time you get ready to power up and only switch to the operator mode only when it is powered up properly. Otherwise you will not be looking for the problem, but be looking to make parts and bummed out when you can't.

Is the Red power off button lit when the breaker is turned on?... every time, even when it will not power up?
When does this red light go off in the power up sequence? when you hear the click in the back?

Do you have 24 volts between P24 and N24 when the breaker is turned on and before you push the power on button?... every time, even when it will not power up?

Have you measured the test points of the power supply when you are holding the power on button and it will not power up? What are the readings?

Up thread I posted "The squeak never happens when the mechanic is in the car!" I mean this, you will be primed to catch the problem and are let down when it works.... but now you can make parts.
BUT when you aren't looking, and you are down because it doesn't work at all. Need to have the right focus.

Been through these kinds of problems many many times over the years.
If it was easy, everyone would want to do it.

With answers to the questions above, we can direct your focus till the problem is found.


Bill
 
You've either got a flakey PD14C control power supply, or something is not letting the PD14C power up and stay on.

Check EBay for a cheap PD14C....I like to swap parts when possible. Sometimes this can burn you, but in this case another PD14 won't hurt a thing.

I have seen complete T2 control chassis and boards go for less than $1,000.

Also, forget Mazak. Call Mitsubishi Electric Automation in Chicago/New Jersey. Ask for a tech who understands T2/M2 controls. A decent tech will be able to flow chart the power up process, hopefully helping you nail it down.

ToolCat


Sent from my iPhone using Tapatalk
 
Hi all,
Thanks again Toolcat I'll give Mitsubishi a call and check out Ebay. Also Bill I appreciate your candor in your reply to my post and for giving me some areas to check. So to answer your questions in the order that you asked.
1) Is the Red power off button lit when the breaker is turned on?... every time, even when it will not power up?
Yes
When does this red light go off in the power up sequence? when you hear the click in the back?
Only when the machine powers up and I hear the main contact relay latch in.
2) Do you have 24 volts between P24 and N24 when the breaker is turned on and before you push the power on button?... every time, even when it will not power up?
To be honest I'm not sure where N24 is in the cabinet. I can tell you at the AVR power supply P24 has 24.1 volts and G24 reads 0.00 as it should and the 100 AC input is present as well . There is also 24.1 volts at the control panel whether the power button is pushed or not. However when the control panel doesn't work the 100AC feed to the control panel is missing and I'm not getting any voltage to the G2A or LY2 relays
3)Have you measured the test points of the power supply when you are holding the power on button and it will not power up? What are the readings?
Answer yes +5v=.001, +12v=.015,-12v=.061,+24v=.413
Once again I was able to start the machine by flipping the main breaker on and off twice before the control powered up. This way of starting the machine has been really consistent.To me it's a pattern .I'll look at the main breaker/Transformer this weekend.
Thanks for the help
Brandon
 
Hi all,
I know it's been quite awhile since I added to this thread. This is the latest and final post on the problem of the start up issue. The problem was a general purpose relay (Omron G4J-1142T)that is located behind the spindle control unit below a bank of big capacitors. The relay is partially responsible for making the SK65 main relay latch in place which in turn makes all of the electronics work in the cabinet.I waited so long to post because I wanted to make sure that this was indeed the problem , I didn't want to say problem fixed and then it happened again. It's been almost 2 months since my last post and the machine has worked flawlessly.I appreciate everybodys help on the issue and I hope this information might help some one else with the same problem I had. Also I can't stand to read an incomplete thread. I wanted y'all to know what I found out.
Thanks again
Brandon
 
Thanks for following up with what the source of the intermittent was.

The circuitry that is involved can be quite confusing as you have found out, I like the statement:
"The relay is partially responsible for making the SK65 main relay latch in"

Bill
 








 
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