Jet 16-42 Inverter Help!

[Russell Neyman]

My 220-volt Jet 16-42 stopped working the other day. No lights in the inverter display, not a sputter. Anyone have any ideas how to troubleshoot the problem? A few bits of background information:

• This isn't the first time this has happened. It doesn't stop working in mid-project, only when I shut it off.
• It the past it inexplicably started working again.
• I worry about wood chips entering the unit through the vents and causing problems, so I often clear it out with compressed air.
• This time, I let a friend use the lathe while I was gone. He unplugged everything when he left and now it's dead.
• I'm not electronically literate.

Is there a reboot process? A reset button? A switch that can get clogged by wood dust? If I open it up, is there more than simply checking for loose connections I should do.

IMG_6553.jpg Jet 16-42 Inverter -1.jpg

[Robert Hayward]

Cannot help you troubleshoot but here is the recommended Delta replacement for your VFD.
At ~$300 seems quite reasonable.

[Dwight Rutherford]

Is power to the lathe through a GFI (Ground Fault Circuit Interrupter) ? Inverters don’t play well with GFIs. Try another circuit for power. If you get a display, look at the back of the Delta S-1, There are two buttons (red & green) labeled “run & Stop/reset”. Push the red one first, then the green.

[Russell Neyman]

If you get a display, look at the back of the Delta S-1, There are two buttons (red & green) labeled “run & Stop/reset”. Push the red one first, then the green.

Will try this and report back.

[Richard Coers]

The most common failure on the 16-42 is that red button switch. Despite being hidden in there, some dust can get into the switch and prevent a solid contact. https://www.youtube.com/watch?v=C_sSqvj1toQ
And discussed here before; https://sawmillcreek.org/showthread....P-EVS-Inverter

[Jason Edwards]

In my experience with inverters, if there are no lights on, you actually have a power supply problem, not an inverter problem. Since this only happens after you shut everything down and then try to restart, this is further indication it may be a power supply problem. As Richard Coers mentioned, the first culprit may be your big red switch on the headstock. Other things to check for are loose connections or breaks in any of the cords and connections going to the lathe. I had a friend drop a chisel on his power cord one time. Took him quite a while to find that and repair his cord.

[Russell Neyman]

In my experience with inverters, if there are no lights on, you actually have a power supply problem, not an inverter problem. Since this only happens after you shut everything down and then try to restart, this is further indication it may be a power supply problem. As Richard Coers mentioned, the first culprit may be your big red switch on the headstock. Other things to check for are loose connections or breaks in any of the cords and connections going to the lathe.

I verified that all the lines INSIDE the inverter were hot. An electronics-savvy friend and I spent an hour looking through the guts of the unit in case it was just a loose connection or broken wire, but found zilch. The wiring is pretty damn complex and probably isn't worth the aggravation to troubleshoot further. I'm buying a new unit.

[Jason Edwards]

I verified that all the lines INSIDE the inverter were hot. An electronics-savvy friend and I spent an hour looking through the guts of the unit in case it was just a loose connection or broken wire, but found zilch. The wiring is pretty damn complex and probably isn't work the aggrivation. I'm buying a new unit.

Well there you go, the exception that proves the rule. Nothing beats good diagnostics. Good luck with your repair.

[Richard Coers]

I verified that all the lines INSIDE the inverter were hot. An electronics-savvy friend and I spent an hour looking through the guts of the unit in case it was just a loose connection or broken wire, but found zilch. The wiring is pretty damn complex and probably isn't worth the aggravation to troubleshoot further. I'm buying a new unit.

You don't think it worth the time to troubleshoot the switch? You prefer to spend 20 times the price for a new VFD? It's up to you.

[Bill Howatt]

I don't understand your comment. They verified the lines inside the inverter were hot, which I take as having voltage applied to them.
If there were no lights on in the inverter I would guess the internal power supply may be the problem but it depends on how things are designed.

[Russell Neyman]

There's power going into the inverter but none going out. As I said before, electronics are far afield for me, but not for the friend who is helping me troubleshoot the problem. The fact that there are no lights showing on the inverter dial would seem to indicate that the problem is there. The last time the machine quit the lights and fan were out, too, but they came back when I blew compressed air into the vents.

[Richard Coers]

I don't understand your comment. They verified the lines inside the inverter were hot, which I take as having voltage applied to them.
If there were no lights on in the inverter I would guess the internal power supply may be the problem but it depends on how things are designed.

If you look at the wiring diagram, the line voltage goes into the VFD first, then goes to the switches. I'm no electrical expert, but assumed there could be some power in the VFD but not have the circuit to start the motor active. There are way more reports of the pot and the switch going bad compared to the VFD.
Screenshot 2023-07-11 at 11.07.11 AM.png

[Bill Howatt]

I read it as the line voltage does go to the block called "sensor" but the pot is driven by 10V and the motion control is achieved by grounding (Gnd) the motion inputs M0 or M1 depending on the direction. However, if the Push/Pull switch is not making contact it would cause the motor not to run because it is not supplying the Gnd and would be worth checking.
However, the OP said there are no lights or any indication on the VFD and the lack of an input to the motion control should not cause that. VFDs typically use low voltage for their controls, not the line voltage.

[Richard Coers]

I read it as the line voltage does go to the block called "sensor" but the pot is driven by 10V and the motion control is achieved by grounding (Gnd) the motion inputs M0 or M1 depending on the direction. However, if the Push/Pull switch is not making contact it would cause the motor not to run because it is not supplying the Gnd and would be worth checking.
However, the OP said there are no lights or any indication on the VFD and the lack of an input to the motion control should not cause that. VFDs typically use low voltage for their controls, not the line voltage.

Your knowledge is greater than mine Bill. But I thought the OPs comment this morning supported my concerns about testing the switch. He said, "There's power going into the inverter but none going out." Doesn't that just prove the breaker is fine? In actuality, we really don't know what his buddy tested. We don't know what current he tested, nor what terminals.

[Russell Neyman]

Here's an update. As indicated earlier, I purchased a refurbished VFD that is exactly the same as the original, using the logic that the connections and mounting holes would match perfectly. They did. It went in easily and the lathe now runs. I've already turned a half dozen projects, both large and small. BUT....

Right away, I noticed that the very top speed wasn't as high as previously, topping out at about 2500 rpm. I called in a technician who, armed with a printout of the VFD manual, who went through the process of restoring the original factory settings, and it still isn't exactly right. The lathe works, but for things like buffing I'd like to have that higher speed. Should I get Jet's Tech Service involved?