Need some help reading and understanding this electrical diagram

[ltlvt]

This is the schematic for my Al/CE 500D power feed for my X axis mill. Although I have 2 new power feeds I bought from Vevor I paid in excess of $400 USD for this one when I bought the PM 833T mill from Quality Machine. No fault of the supplier I made the stupid mistake of plugging it into 220 volt and it is a 110 volt unit. Just a pop and I unplugged it and at that moment I realized I screwed up. Now I am trying to repair it. I have taken it apart and did a first look visual inspection of the inside including the pc board. Nothing visually that I can see got burned. It does have a circuit breaker that I would like to verify is working or not working before I go further. In order to get the breaker out it clipped in but I would like to check it in position before I go to the trouble of removing it and replacing it. But I can't get the shift lever off that controls the direction of travel. So the help I am requesting is how to remove the shift handle. I have already removed the speed control pot knob and also removed the set screw in the shift lever. Any ideas would be certainly appreciated. The next issue I need help with is understanding the schematic for the unit. I understand L-1 N for neutral and the upside-down Christmas tree means ground or Earth. But the rest of the components are unnamed and Greek to me. So any help in identifying components in the schematic will be a great value to me. Thanks in advance for any help on either issue. One of my goals this winter is to learn how to troubleshoot PC boards and therefore repair some items such as my Snap-On Mig welder. Tomorrow, I aim to install a new SSD hard drive and RAM in a Dell Notebook of mine. And boot it up with Linux Mint USB disc.

 

[RJSakowski]

I would check the SCR's. I didn't see any other components that would be particularly vulnerable.

 

[markba633csi]

It's a difficult schematic to follow even for me and I'm somewhat familiar- weird diode symbols too
The way they have wires crossing over which may or may not be connected is confusing
I'm with RJ probably one or both of the SCRs are blown and possibly one or more diodes
Many of the diodes can be tested in place with a ohmmeter but SCRs should be unsoldered to test
Diodes: 6A40, 5404, 4007
SCRs: S4006LS2 6amp, 400 volt, sensitive gate, isolated tab

You can build a test fixture with a small automotive bulb (not a headlight) and a 9 to 12v battery or power supply:
Momentarily short the anode to gate, the lamp should light and remain lit until power is disconnected.
If lamp doesn't light or lights without gate control the SCR is bad.
Diodes can be checked also: should only light lamp with cathode down. If lamp doesn't light or lights in both directions diode is bad.

 

[ltlvt]

It's a difficult schematic to follow even for me and I'm somewhat familiar- weird diode symbols too
The way they have wires crossing over which may or may not be connected is confusing
I'm with RJ probably one or both of the SCRs are blown and possibly one or more diodes
Many of the diodes can be tested in place with a ohmmeter but SCRs should be unsoldered to test
Diodes: 6A40, 5404, 4007
SCRs: S4006LS2 6amp, 400 volt, sensitive gate, isolated tab
You can build a test fixture with a small automotive bulb (not a headlight) and a 9 to 12v battery or power supply:
Momentarily short the anode to gate, the lamp should light and remain lit until power is disconnected.
If lamp doesn't light or lights without gate control the SCR is bad.
Diodes can be checked also: should only light lamp with cathode down. If lamp doesn't light or lights in both directions diode is bad.
View attachment 468176

Thanks.

 

[ltlvt]

I would check the SCR's. I didn't see any other components that would be particularly vulnerable.

Thanks

 

[homebrewed]

It's a difficult schematic to follow even for me and I'm somewhat familiar- weird diode symbols too
The way they have wires crossing over which may or may not be connected is confusing
I'm with RJ probably one or both of the SCRs are blown and possibly one or more diodes
Many of the diodes can be tested in place with a ohmmeter but SCRs should be removed to test
Diodes: 6A40, 5404, 4007
SCRs: 4006LS2
You can build a test fixture with a small automotive bulb (not a headlight) and a 9 to 12v battery or power supply:
Momentarily short the anode to gate, the lamp should light and remain lit until power is disconnected.
If lamp doesn't light or lights without gate control the SCR is bad.
Diodes can be checked also: should only light lamp with cathode down. If lamp doesn't light or lights in both directions diode is bad.
View attachment 468176

I agree that the schematic symbols are pretty strange. I'm wondering if that rectangular symbol that's apparently in series with the "L" input is a fuse. Hard to tell, given the nonstandard symbols. Check it out, if it IS a fuse maybe it blew open.

I also see an electrolytic capacitor in the speed control block. It looks like it's a 470 microfarad capacitor. Take a look at it to see what its voltage rating is. For 120V it should be at LEAST 170V, and that would be on the hairy edge of blowing up. To survive 220V it would need to have a working voltage greater than 220*1.4 = 311V. The AC voltage is an RMS value so the peak voltage is sqrt(2) times higher than that.

If you're not sure what you are looking for, take a photo of the board and post it. There are many electronic-savvy folks on this forum that can help you out with this.

Also, your eyeball and sense of smell can be diagnostic tools. Anything look burnt? Smell burnt?

Hopefully all your circuit board traces are intact. An extreme overload can actually vaporize circuit traces, I've seen it! And it was my fault....

 

[ltlvt]

I agree that the schematic symbols are pretty strange. I'm wondering if that rectangular symbol that's apparently in series with the "L" input is a fuse. Hard to tell, given the nonstandard symbols. Check it out, if it IS a fuse maybe it blew open.

I also see an electrolytic capacitor in the speed control block. It looks like it's a 470 microfarad capacitor. Take a look at it to see what its voltage rating is. For 120V it should be at LEAST 170V, and that would be on the hairy edge of blowing up. To survive 220V it would need to have a working voltage greater than 220*1.4 = 311V. The AC voltage is an RMS value so the peak voltage is sqrt(2) times higher than that.

If you're not sure what you are looking for, take a photo of the board and post it. There are many electronic-savvy folks on this forum that can help you out with this.

Also, your eyeball and sense of smell can be diagnostic tools. Anything look burnt? Smell burnt?

Hopefully all your circuit board traces are intact. An extreme overload can actually vaporize circuit traces, I've seen it! And it was my fault....

I plan on bringing it into the house tomorrow and pull the board out. I will take pics then and post them. I can see the back side of the board and all the traces look fine. I will have plenty of time to work on it tomorrow because the Dell Notebook I bought the new hard drive and ram for is not upgradable. I took it apart tonight and best I can tell it does not even have a hard drive that is visible. Maybe it works from the Cloud. So, I will be returning the SSD hard drive and 8 gig RAM. Some of the Inspiron 3080 Notebooks are upgradable but my luck I have one that is not. If I knew how to wipe the current Hard drive, I would do so and reload the OS but with Linux Mint. The computer works but slow as thick mud and keeps saying low on disc space. I think someone from cyber space must have corrupted it. Thanks a million for your kind advice.

 

[homebrewed]

I plan on bringing it into the house tomorrow and pull the board out. I will take pics then and post them. I can see the back side of the board and all the traces look fine. I will have plenty of time to work on it tomorrow because the Dell Notebook I bought the new hard drive and ram for is not upgradable. I took it apart tonight and best I can tell it does not even have a hard drive that is visible. Maybe it works from the Cloud. So, I will be returning the SSD hard drive and 8 gig RAM. Some of the Inspiron 3080 Notebooks are upgradable but my luck I have one that is not. If I knew how to wipe the current Hard drive, I would do so and reload the OS but with Linux Mint. The computer works but slow as thick mud and keeps saying low on disc space. I think someone from cyber space must have corrupted it. Thanks a million for your kind advice.

Many linux installers are pretty smart these days. We have 5 computers running various flavors of Ubuntu (some are dedicated servers for things like networked printers, some massive overkill there). But I did run into a problem with our most recent acquisition, where the second HD was recognized as read-only. It had been in a Win10 system and configured with the fast start option, which seems to be something that current flavors of linux don't handle very well. It was necessary to completely reformat the drive in order to use it as a r/w drive.

Booting linux from a live CD can often tell you how well it will run with your hardware, before you do something you can't un-do. I have tossed many distros because they clearly didn't work well with my computer, but with the live CD approach it wasn't that big of a deal. I have installed older linux versions on older laptops and seen a substantial performance improvement compared to Windows so that's a very viable approach to extending the life of an older computer system. It just may take some trial and error to find a version that works with your particular computer.

 

[ltlvt]

Many linux installers are pretty smart these days. We have 5 computers running various flavors of Ubuntu (some are dedicated servers for things like networked printers, some massive overkill there). But I did run into a problem with our most recent acquisition, where the second HD was recognized as read-only. It had been in a Win10 system and configured with the fast start option, which seems to be something that current flavors of linux don't handle very well. It was necessary to completely reformat the drive in order to use it as a r/w drive.

Booting linux from a live CD can often tell you how well it will run with your hardware, before you do something you can't un-do. I have tossed many distros because they clearly didn't work well with my computer, but with the live CD approach it wasn't that big of a deal. I have installed older linux versions on older laptops and seen a substantial performance improvement compared to Windows so that's a very viable approach to extending the life of an older computer system. It just may take some trial and error to find a version that works with your particular computer.

I've done some research since my last post, and it looks like the SSD hard drive and 8 Gig RAM will work on my OptiPlex 360 so I may not return it.

 

[homebrewed]

I

I've done some research since my last post, and it looks like the SSD hard drive and 8 Gig RAM will work on my OptiPlex 360 so I may not return it.

Standard drives should almost always work OK with linux. The fast-boot thing is the only time I really have had problems with using a drive with linux; and, fortunately, that was not the boot drive. Sounds strange, but it was true. Linux installed just fine on the boot disk but the other HD, apparently only meant to be used for backup purposes, took some work to make it usable under linux. I really wanted to use it, it's a 1TB drive.