[judleroy]

The machine is a bmc30 ssm from around 97. As some of you may have read in my other posts over the years its been no end to my heartache.
My newest question is this. How do I test the power supply on the left side of the cardrack. On the top left corner of the cardrack there is a board with test points on it. The points run up and down. There is one at the top and then a space then four more points below that. My problem is where to put the com lead from the meter in order to test. Also what should each point test for voltage. I'm lost so how would you guys do this.
One more question also. The main power coming in for my three phase supply to machine. There are three wires and a ground. The wires have voltages of 120v , 120v , and 220v. How do I know if these are run correctly to the machine. I have run the machine the way its wired now before it stopped working. Does that mean it should be right?
Thanks for everyone's help.(i know its my lack of understanding that's my biggest obstacle)
Judleroy

[bloke]

The test points first.
There are five of them. the one on it's own is the 0v common.
then, moving away from the 0v, in this order and measured relative to 0v:
-12v
5v
12v
24v

You should have on your incoming supply (relative to ground) 120v per phase or 220v between all the phases. If oyu don't, you may have a fuse gone on the incoming supply.
Turn the isolator off to measure the incoming supply as you have a transformer that will create the impression that you have a low phase if one is open.

[judleroy]

Ok thanks for the info bloke. This is what I get. When I turn on control power everything comes on or so it seems. The canbus controller leds come on but the computer doesn't boot. When I tested to 0v relative to -12v and 5v I got no reading then to 12v the pin arced and the leds that were lit on the canbus flashed off then came back on when I pulled the meter off the pin? I'm at a loss. Any suggestions? Thanks
Judleroy

[fasto]

Set your meter for DC Volts, not DC Amps.

[judleroy]

I had it set to 20vdc. Thanks
Judleroy

[fasto]

If the pin arced when you touched it with the voltmeter probe and you had the voltmeter set on 20VDC, there's something wrong with the voltmeter. The lights going out and coming back on show that you were shorting out the power supply.
Make sure the meter leads are plugged into the proper connections. These are probably labeled COM and something like V/Ohm. Make sure you're not plugged into a terminal on the meter labeled A or Amp.
What type voltmeter are you using?

[judleroy]

Thanks fasto my bad. I will try again tonight and report back.
Judleroy

[judleroy]

Ok I think I got it tested right. There was one issue. I read 0v for the -12v. The 5v measured 5.14, 12v was 12.4v and 24v was 25.5v. I'm not sure if I tested the -12v correctly but if it is tested on the same settings as the rest then it is not present and reads -0.0v. Will this cause the machine not to startup? If the machine were started up and it went out would everything shutdown like what happens to me. If this may fix my issues I will try fixing it if not it's on to a retrofit. Any advice for moving forward would be yearly appreciated. Thanks for all the advice so far bloke and fasto.
Judleroy

[TarHeelTom]

Ok I think I got it tested right. There was one issue. I read 0v for the -12v. The 5v measured 5.14, 12v was 12.4v and 24v was 25.5v. I'm not sure if I tested the -12v correctly but if it is tested on the same settings as the rest then it is not present and reads -0.0v. Will this cause the machine not to startup? If the machine were started up and it went out would everything shutdown like what happens to me. If this may fix my issues I will try fixing it if not it's on to a retrofit. Any advice for moving forward would be yearly appreciated. Thanks for all the advice so far bloke and fasto.
Judleroy

Many machines have a separate fuse for each voltage from the power supply. First thing I'd do is to look to see if your machine has these fuses, and if so, is one of them blown.

If not, search out someone locally who works on electronics. Many ham radio operators are pretty good with troubleshooting. See if one of them can trouble shoot the power supply for you.

Tom

[judleroy]

Thanks tom.There is a local place that can fix the supply. Before I have anything else repaired that is suppose to fix the machine but really won't I need to know what the -12v is for in the machine. If it is not present will the machine still start like normal? I have read that -12v is used for rs232 in older pcs. Is it used for anything else? Thanks
Judleroy

[TarHeelTom]

Thanks tom.There is a local place that can fix the supply. Before I have anything else repaired that is suppose to fix the machine but really won't I need to know what the -12v is for in the machine. If it is not present will the machine still start like normal? I have read that -12v is used for rs232 in older pcs. Is it used for anything else? Thanks
Judleroy

I don't have a clue, as I'm not at all familiar with your machine. Was taking a shot off the top of my head based on general electrical knowledge.

They may well find that your power supply doesn't even have a -12 supply, but the test point was already there, so they ignored it.

[bloke]

The -12v is used by the motion control system to generate the DAC voltage for the servos and spindle (in conjuction with the 12v).
The control will start without it. Are you checking it with a digital voltmeter? Try reversing your meter leads to see if it appears as a positive voltage.
It's very rare to see the supply lose just the -12v. Normally, if this happened whilst running, the axes would move in one direction only.

[judleroy]

Ok lets try again. I tested the dc and its good. The machine still would not startup. I pulled the graphics board that I had "repaired" and found a place where it looked like they burned of a trace and then ran a small copper wire that was soldered to where the trace ended. It was going to one of the moniter outputs. It looks like they just glued it in place so it would work when I got it. The wire had seperated and was no longer glued to the trace. I took some electrical tape and taped the wire in place to try and see if that was the problem. I reseated the board and the machine started like normal. Wow. I turned it on and off several times and it started 4 out of 5 times. Everything worked fine. Spindle, servos, Tool changer etc. The questions are first do you think that little wire was my problem with the machine not starting?
Now that the machine is running there is something bothering me. When I jog the axis or toggle tools there is no problem. When my spindle is started the screen starts to wave around like water rippling. Everything is still there but it waves back and forth about 3/16" like water.Is this a power or grounding problem or still just a problem with the graphics board? Maybe I'm way off base.
Thanks for any help.
Judleroy.

[bloke]

The wire was a shield that reduced noise.

[judleroy]

I talked to the people who were supposed to fix the doses today. They told me they new they had messed up the trace and the wire was from the termination and glued to where the trace was still good. It was a really bad emergency fix to hide a mistake.
That is something I can fix even if they can't. What I really need to know now is why the spindle starting causes moniter issues. Just so nobody thinks I'm crazy ill take pictures of the bad trace and a video of the moniter messing up and post them here tonight.
Thanks
Judleroy

[fasto]

I'm assuming you've still got CRT tube monitors? These are sensitive to really only 2 things:
#1 Magnetic fields will cause wavy lines or bleeding colors.
#2 Voltage fluctuations can cause wavy lines, or changing brightness.
This assumes that the monitors themselves are working correctly.

If you check for loose wires you can probably eliminate #2, although I think you shorted out the power supplies while you were checking them earlier. This could cause the power supplies to not work properly either by not holding voltage under load or by making excessive AC ripple.

The spindle motor running could radiate magnetic fields out its wires, or cause voltage fluctuations under some circumstances. If the display waviness changes with spindle speeds that would help diagnose what's causing it.

If you're uncertain about fixing the bad trace on the board you could send it to me and I'll fix it no charge.

[judleroy]

Thank you so much fasto. Thats what I was wondering. The machine ran for 4 hours straight today. I just ran the warmup cycle back to back. The wavyness was less pronounced but I think I found a better indicator. When the spindle spins very fast(6000-8000 rpm) or very slow (below 300 rpm) or is oriented the graphics screen flashes on and off. The graphics screen is not a crt like the main screen. It is a old color computer moniter pluged in instead. It is powerd by a plug to an outlet. The other is a crt and is powered by the machine. You can plug in any moniter and the machine will display in 16 colors. Since the bad trace goes to the graphics display plug I guess the bad connection could be causing my issues. I will try to fix the board with a trace pen. I would post videos but cant get them out of my phone.(will keep trying) After all these years i'll be shocked if I fixed this thing with a piece of tape.
The big question is Why does a bad connection on the moniter plugout on the board keep the machine from starting? Was it really my problem all along?
Thanks
Judleroy

[judleroy]

Ok I again want to thank everyone for trying so hard to help over the years. I finally removed the pc supply from the machine and had an electronics tech test it. He let it run for an hour or two before testing. He showed all the voltages good except the 5v. He found no 5v at all. What I'm wondering is if he brings in the5v from a regular pc supply will it hurt to keep using the other voltages that are still good from the original supply or do I need to nix the whole original supply? Could it cause any problems? Thanks.
Judleroy

[fasto]

judleroy you could patch in the +5V from another power supply.
If it were me I wouldn't do that. I'd get a PC computer power supply and wire it up to the +5V, +12V and -12V. I'd get a separate 24V, 5A power supply for the +24V. Recently on this list another guy did that with his machine, look at that thread for some more info.

[john-100]

Hi Fasto ,

is this the link you mean :--

http://www.cnczone.com/forums/hurco/..._supply_w.html


John