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Mits DWC90C1 trouble shooting

mymachinery

Aluminum
Joined
Apr 4, 2007
Location
McBEE, SC
I hope someone has some experience with this problem: I got this new to me machine hooked up & running, but it only cuts very slow, around .012"/min in 1/2" steel. It did start cutting fast (.117"/min) one time, and I was so amazed that I stopped the machine to admire the work piece, and when I started cutting again it cut very slowly again. While cutting I have checked the voltage and it was corresponding to the control screen reading of 49V. I haven't found anywhere to check the amperage as the cables are all shielded. So far, I have checked the power feed contacts, dielectric resistivity,any fuse I can find, various circuit board cable connections,

Does anyone have any ideas? Pulling my hair out here
 
Well a few weeks ago I got it to cut much faster one more time. Like before, once stopped, it starts slow the next time, same settings, same everything. I am seriously considering getting the machine registered, but first I am getting a different generator to try (supposedly out of a running machine that was parted).
Every time I find something slightly not correct & fix it, I think "wow,this it what's wrong, it's going to work now", but it never does. I measured the 100v signal and moved the transformer jumpers from 220v to 200v and now the 100v terminal measures 103v- that didn't fix it. Both upper & lower power leads were bolted slightly loose, but cleaning and tightening the connections didn't help at all. I have been reading lots of posts here and have decided to do like some of our members have & buy extra circuit boards for insurance, if I get it working that is.
There is one more problem I have noticed that might be unrelated or a clue, that is the DI pump doesn't run to keep the notch number right, I have to turn it on by lowering the commanded notch to 3, and then stop it by raising it back up.
Any Ideas?
 
The other day I removed the DC module and the one next to it for inspection. I blew out the dust, checked for obvious blown devices or broken connection. I also checked the ohms on every relay across the magnet and the contacts. I had a small hope as one cable connection latch was loose & I wasn't sure it was connected fully. I did find two devises that I believe to be capacitors, they are largish rectangular blocks with two lead out posts. I checked them with a multimeter in ohms setting and it is possible that one is bad. It is a MCQ90P3E. 502KSI-X SOSHIN434. I look all over the web & couldn't find any ref to it for farad size or voltage.
Anyway, I put everything back together & it still cuts slow. Well at least I didn't break anything in my exploration.
Ideas anyone? Still considering the MC solution, just don't want to pay to find out I have a terminal case of won't work
 

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Hi,

Did you measured in Ohms with everything connected? If it is the case the measurement is not ok because the connections can affect your result, also they're feedback cables.

In my experience I can tell that when more difficult is to find a problem, the biggest small thing is the problem and is not easy to find it unless you have the correct info and sort of knowledge and of course good luck.

In my opinion the tech service in your country could find the issue as some people talk very well of them.
I'm sorry in this particular case I couldn't help more but I'm specialized from FX to modern machines.

Best Regards.

Best Regards.
 
Mitsu tech Spain, first,thanks for your previous help. Yes I did pull devices from their sockets to check. I also purchased & swapped in a different generator unit that was supposed to be from a running machine with no changes.
Last night I rebooted the machine because it wasn't responding to the system ready button after my exploration. I then tried cutting again, and even used the Epack for 100mm skd11 on a 1/2" test subject. Still will not cut over .012" min, I have never had the wire break or burn in two.
 
Hey mymachinery, I believe I'm having the same issue or very similar on 2 of my machines, I have 3 of these 90C's. The machine I've owned and ran the longest that was also the least maintained to start with doesn't miss a beat. The first problematic machine did this out of nowhere and the second problematic one started the exact same issue a few months later also out of nowhere. The only thing that may have something to do with my issue is the machine wasn't ran for maybe a week or so after running almost daily. The problem arose with that first initial run after sitting a bit. Having said that the machines have sat for extended periods in the past, such as a week or more, since I first put them into service over a year ago. I went to run one of our normal everyday cuts, at the start of the cut the machine only feeds anywhere from 0 to 0.010", it kinda jumps around in that zone, no faster. The only way to squeeze a tiny bit more is speed the wire way up. It doesn't try to break the wire or give any weird actions like a setting is off, it's like the feed is just turned way down although it's not. The second machine started doing the exact same thing a few months later. I have checked all of the "normal" things such as contacts, guides, rollers, DI stuff, etc. and reloaded software. Everything seems to be under normal conditions for my machines. I've also been contemplating taking the leap of the service contract but hate to do that and end up spending way more on the machines than what they can be purchased for these days. I paid less than $4k each for 2 of mine. I reached out to a previous owner who's brother is a current 90c operator and was told it's possibly a DC drive/unit? I don't even know where to start in the cabinets other than the main boards which I have very little experience with. Have you had any luck with your issue?
 
DC, I have tried not thinking about it this month, I had to stop dicking with it & make some money with I jobs I already have. I am going to sign up with MC in the morning and either fix this machine or blow it up for good.
I will let everyone know the outcome. I was talking to a service guy today to get more info on what I get for $1750. If I have boards that are suspect I can send them in for an operational check for something like $100., but he said that usually they can get to the bottom of the trouble shooting over the phone if you can verify voltages, signals, etc.
So here we go, I have to either make it or break it.
 
DC, I have tried not thinking about it this month, I had to stop dicking with it & make some money with I jobs I already have. I am going to sign up with MC in the morning and either fix this machine or blow it up for good.
I will let everyone know the outcome. I was talking to a service guy today to get more info on what I get for $1750. If I have boards that are suspect I can send them in for an operational check for something like $100., but he said that usually they can get to the bottom of the trouble shooting over the phone if you can verify voltages, signals, etc.
So here we go, I have to either make it or break it.

Good luck. For what it's worth, paying the support was the best thing I did years ago. Their phone and email support is second to none and has helped me several times over the years. It's been priceless. Please update us!
 
OK I got registered, logged on today & got a trouble request logged. A tech called back fairly quickly & after a recounting of the machine history & major malfunction he emailed two pages of things to check, all voltage checks with different inputs. unfortunately, while I was waiting for his call back to review my data, I had turned the machine off. When it was booted back up, everything went dark after about 10 seconds. The machine now has a 702 alarm related to the water quality probe. Also, now the water, wire, & machining wont turn on. The tech said to disconnect the cannon plug and jump the U & V terminals to see if the alarm could be cancelled, but that didn't help. After some research, the Tech thought it is the C300 PCB . This MIFB-C300 designation isn't on any of the PCB in the area that it is supposed to be in, all the PCB I see is starting with BY17.
I would rather ID the PCB , get it out and verify that it isn't something stupid like a blown capacitor, bad solder, etc rather that getting the PCB in the mail to figure out what it looks like, fix the stupid, then pay a restocking fee. I was working against their 5PM Friday schedule and ran out the clock for this week, so I hope Monday I can get some more accurate info to ID the PCB so I don't take apart anything unnecessary and really screw up.
A few days before all this, I was talking to the regional service rep to get reg & he said it sounded like I was getting voltage, but not current and that they come from two different places. Hopefully one fix will solve all the problems.
 
Hi,
Can you take a picture of the alarm page to show the exact alarm, if it's U702 LR out of Control, it sometimes comes from the overload of the pumps which are found in the electrical box on the dielectric tank. You might have lost a phase to the machine??? causing the pump motor to overload? In my experience (30 years with Mitsubishi EDM in UK) its always been this, or the chiller has an alarm, but usually there is a fan cooler fitted to 90C machines, and this has no feedback to the control. This alarm will not allow you to turn on the Fluid or machining. Give it a look, costs nothing!
 
Yes, the tech said that alarm was indicating an overload was tripped. I checked all the relays and nothing was needing to be reset. The purpose of the jumper was to close the circuit to mimic the heater as not tripped. Since the jumper still didn't let the controller reset the alarm, he thinks it indicates a bad board. For what is worth, I did manually close the contactor contacts & ran the pumps, etc with no obvious problems. I guess I could try the meter for continuity across the relay overload contacts, and put an amp clamp on the motor leads & check for over amperage.
 
Ok, so I have tried two different MIFC pcb and still have the 728 alarm. Everything in the wire box checks good; the harness, the floats, the motor. When you move the floats, the computer is not changing the bits from 0 to 1, or the other way around. Before really going deep $, I was thinking that what if the pcb was getting no voltage or bad voltage. After checking a small power supply that should be 5v, +12v, -12v, one of the 12v legs had scattered readings from 11v to 6v. I have ordered a used power supply & it should be here on Monday. I would be interested in a nice new equivalent supply as the OEM one is obsolete, but for now I just went used so I didn't have to fuss with a different mounting or cable scheme. One other possible thing could be the Fw01 pcb, but I pulled it & inspected for anything irregular- it looks good, for now at least.
 
Ok, I just installed a genuine MIFC pcb from MC Mach,spent big money, no change, can't resolve this 729 alarm code. I checked the ohms for the wire box pump, it checks 53 ohms, does that seem a little low? Is it possible that the motor is bad? But how would the board know anyway if it isn't sending it voltage?
 
From info I have received on the slow cutting issue: disconnect & remove your DC module. Get 120v pigtail lead and hook it up up to the input B on AVR2. Power up the AVR's and read the output voltages on all the AVRs they usually have labels showing the out puts in DC V. There are several different kinds reading from 15v , 5v 12+/12-, 24v. If you find one that isn't reading correct DCv, then replace it.
 
From info I have received on the slow cutting issue: disconnect & remove your DC module. Get 120v pigtail lead and hook it up up to the input B on AVR2. Power up the AVR's and read the output voltages on all the AVRs they usually have labels showing the out puts in DC V. There are several different kinds reading from 15v , 5v 12+/12-, 24v. If you find one that isn't reading correct DCv, then replace it.

Have you got the machine up and running yet ?
 
No, I tried a different FW01c pcb, but it wouldn't even let me load the OP sys, so I sent it back. I guess I am going to mail my FW01C to MC Mach for an ops test. Really starting to wonder if they have a handle on this machine. Seems to be a lot of shooting in the dark for factory experts.
 
Just realized the trial FW01C board probably would have worked if I had thought to swap in the original eproms. Stupid mistake. I have a different pcb on the way & then I will give it a go.
 
Ok, I got a secondhand Fw01 pcb, swapped in the original eproms. The op system loaded & I can jog around, but now there is a different alarm, I believe a #518
 
From info I have received on the slow cutting issue: disconnect & remove your DC module. Get 120v pigtail lead and hook it up up to the input B on AVR2. Power up the AVR's and read the output voltages on all the AVRs they usually have labels showing the out puts in DC V. There are several different kinds reading from 15v , 5v 12+/12-, 24v. If you find one that isn't reading correct DCv, then replace it.

The DC module is the smaller black box about waist high in the cabinet correct?
 








 
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