A retrofit of a Stanko SMO 32 CNC milling machine (Ukrainian clone of a Maho)

Yes, there's 24V on both 302 and 301 lines. And yes, 19A1 is the CNC controller ie Heidenhain LE 360C. It has all the voltages it needs (24V, 5V etc, all the LEDs are on). There is also a blinking LED on the board, which according to the manual means that the controller is operational.

So I think what you suggest is correct, ie. this must have to do something with the inputs. The problem is that this part of the wiring differs from the schematics. For example at the column 278 here there are some switches that are described as "microswitches of the enclosure, lock":

 

so my first thought was: OK, maybe it's something as dumb as some kind of switch that checks if the enclosure is opened, but then I couldn't find any switch like that and it turned out that the points listed there (403, 456) are not connected to the input. Which looks like maybe on some machines there were switches like that, but not on that particular machines. I will still maybe go over some of the points that are in fact connected to the inputs over the weekend, but I agree with you - if it's not something I can catch quickly, it won't be worth it to debug the thing. Especially that I can probably sell the controller and the display/keyboard assembly for a decent price. One drawback of getting rid of the entire controller will be that I will have to give up the EXE components as they are integrated inside the controller, but there's lots of standalone EXE modules on Ebay and most of them are in 60-80EUR range, so that's not a big problem. And then the placement of the controller would work great for a motherboard with LinuxCNC, so again, I would prefer to get rid of it.

Anyways, I'll write an update soon, but I'm close to pull the trigger on the Mesa cards

 

I totally missed the asterisk, that would make sense, thanks! In any case when I have more time I plan to do a list of all of the connections for inputs and outputs of the CNC controller and figure out if anything might be wrong in there.

I had only a few minutes of time for any debugging today, so I only made a list of all the points where the X22 (inputs) wires are connected: 160, 303, 376, 400, 401, 402, 405, 406, 407, 408, 420, 421

Points 160 and 303 are basically connected to ground.

376 is quite interesting - it's coupled with node 307, which is one of the outputs which is one of the outputs. In the column 271 it's described as a "reaction for the function M, T". In the column 234 (for the outputs) it's described as "address M". Not sure what that could mean, sth about a motor? I'll need to check the voltage on the node 307 and if the contactor connected there works correctly.

400-402 points are for the motor control, likely not important for starting up.

405-421 look like they're used when changing gears, so again, most likely not important for startup

Omg, I'm so dumb Thanks a lot and no, I didn't know about this part of the manual! My German is quite basic, so I was translating only selected parts of the manual and I haven't realized there is anything like that. Skimming through those pages now seems like they might have been very helpful in the past weeks lol. I'll do a translation so I can understand it better

> Are you still only getting fault "47" on the indicator in the electric cabinet (Störstellenmelder) ?

Yes, but I think it would go away as soon as I'm able to fix whatever the problem with the controller is

I think I'm getting somewhere. This whole time I was so focused on chasing the farther and farther contactors that I missed a mistake I made at the very beginning. At some point I mentioned the button that bypasses some of the contactors in order to start the hydraulic units (lubrication and power hydraulic). Back then I haven't thought about it that much, but now that I was going through the whole thing again I realized that I have never heard the hydraulic power unit to turn on *unless* I pressed the 3K1 contactor. So I looked at the schematics again and there's a 3F1 (fuse?) thing before the 3K1 contactor in the column 170:

 

So I checked the nodes 166 and 167 and sure enough there was 110V between 166 and the ground and no voltage on 167.

Now I started looking for the 3F1 device and it's on the hydraulic pump:

 

Before I thought that it's a pressure check, but now I'm not sure. Anyone with the similar pump knows how this thing works?

Now that I'm thinking about it maybe it's a minimum oil level check. There are no markings on the minimum level and the pressure gauge is on the right I think. So maybe I just need to add oil?

I found such a device on an auction and it's apparently a pressure switch, which would make sense when looking at the schematics - whenever it reaches the desired pressure it will turn off the pump. And according to the schematics it's normally closed. The question is, why it's acting like it's open? Might still be some kind of level of oil measure connected with the switch, so I guess I'll buy some hydraulic oil (which I would have to do anyway I guess).

update:

There is something definitely going on in there. I unscrewed the top of the device to uncover contacts and there is a connection between the contacts when the machine is off. But then as soon as the voltage comes in the connection is closed. I thought that maybe the pump is getting up to the pressure too fast to notice, but that would be weird. Just in case I asked another person to hold the "hydraulics on" button while I was looking at the pump and it didn't move at all, so yeah, it seems that something is off about the pressure switch. I will buy the oil to top it up just in case, but if that won't help I'll maybe buy a replacement switch.