[jschoch]

I was drilling some holes with my mill and got a nasty shock. Turns out there is 60+v flowing from the set screw on the potentiometer to the frame. Now the motor will not spin and I'm wondering how to trouble shoot.

1. there is still current running from the set screw on the speed control pot to the frame. Oddly it registered as 120 AC, then back to ~60v DC after cycling the safety switch.
2. Popping off the e-stop cover shows the green light iluminating. Fan in the control box spins up and a red LED iluminates inside the control box (you can see it through plastic).
3. hitting e-stop triggers amber light above stop button. Returning the pot to off resets amber light.
4. Fuse is un-blown and checks out via OHM test.

I really don't want to have to return this thing after cleaning it and tramming it in. Any ideas on how I can trouble shoot this? I peeked inside both boxes and there isn't anything obviously blown or loose. The big mosfets seem ok but I did not attempt to probe them.

[rcheli]

I would take a look at the potentiometer and see if one of the wire lugs is bent over and is touching the potentiometer case.

[jschoch]

I would take a look at the potentiometer and see if one of the wire lugs is bent over and is touching the potentiometer case.

it does not look like the pot has bent lugs. There definately is 120AC potential going from the pot to the frame. With the power off I poked around a bit inside the main board and it looked like hot/neutral was backwards. I swapped them but still don't see any response. I put my probes on the DC output connections and see zero voltage. I'm going to try to hook up my bench supply and see if the motor turns on with an external source. I really don't want to poke around the box/board too much since this is all sorts of scary with no isolation. I'm only really familiar with low voltage DC. I got hit by AC about 20 years ago and it keeps me from trying anything creative

Anyone know what to expect from HF? I submitted a request to their customer support. Should I call tomorrow?

[jschoch]

I checked the big diode and the bridge rectifier. Both seem ok. I notice I get no relay click when I turn the pot switch, perhaps that is the problem? I checked the "motor" relay which is jumpered on terminal 6/7. that works fine and is on by default when you plug it in (that's what the jumper does).

It also appears the pot switch is normally closed from my testing of it unplugged.


This is a really good description of the board.

https://78462f86-a-59bfe619-s-sites....viceManual.pdf

[jschoch]

Well, after a week of waiting on the claims department I have no information on whey they want to do and no expectation on when they might get back to me. The phone number rings to voicemail always and they have not replied to my emails.

Sometimes you only remember great customer service when you are stuck with the opposite

[rcheli]

If you decide you would just like to get the control board fixed I would contact this guy. I accidentally shorted the E-Stop circuit to ground and blew a part on the board of my HF X3 mill. I got very good and fast service. Go to his website MINI LATHE - MILL BOARD REPAIR SERVICE and click on trouble shooting and you might find what you need there. If not, click on service detail for info on how to proceed with sending him your board for repair.


Pete Brush (Olduhfguy)

Shipping address:

Repair Service
196 North Clary Road
Jefferson, ME 04348

web: MINI LATHE - MILL BOARD REPAIR SERVICE
Facebook: https://www.facebook.com/repaircontroller
Feedback: https://olduhfguy.wordpress.com/2013...fguy/#comments

[jschoch]

thanks, for the tip

4 weeks later and not a single response from HF other than "hang on to it". I already bought another mill and I'm glad I didn't wait around for them to respond. I sure hope they refund me fully and for the shipping.

I bought a grizzly on ebay as a show room item. At least the customer support is responding but I'm not exactly having a great experience there either. I guess I should have bought a PM25