My lathe is dead

[saw]

I brought my lathe in January this year and I have had a good time with it, but now it's dead. 

The modell name is: JC0618A
What was happening? I don't know, I took some turn on the lathe, and then stop, then I should take some more turns, and nothing happend.  .

I took some help from my son i law, he is working as a  reparatur and installer for plasma and laser cutting machines, so I thought that he could help me. We found out that the potentiometer was broken so I order one from http://littlemachineshop.com/.
Today I'll got the item, mount it and bang, it was an short circuit  .
The only wiring diagram I found (I can't find any one) was this:

And this don't say anything, it's not helpfull. What to do ??? 
 

[Jonny]

Its a common problem with the non US circuit board. If its repaired it will keep happening.

Info will be on here some where.
http://www.mini-lathe.com/Default.htm

[Chuck in E. TN]

Benni,
Have you tried the Drive Troubleshooting guide here?

http://www.littlemachineshop.com/Reference/reference.php

Chuck in E. TN

[Rob.Wilson]

Bad luck Benni 


I hope you  fined a fix 


Rob

[saw]

Thanks every one, yes I have tryed the Drive Troubleshooting guide  but so far no luck .
Looking at the PCB one of them looks burn... 
I will try to talk to my supplier tomorrow and see what to do,  maybe the scrap heap

[Stilldrillin]

Benni.
I hope you have the same good advice as I had, when my lathe went POP.......   http://madmodder.net/index.php?topic=4962.0

I felt lost and alone for the first few hours, until the help started to arrive from those who know.

Good luck! 

David D

[raynerd]

Saw, is it totally dead or is it constantly tripping the fuse? I haven`t a clue if the board on the lathe is similar to the board on my X2, but I had a shorting problem and found it was the bridge rectifier. Like i say, I haven`t a clue with electronics but for the sake of checking it may be worth while??

http://www.raynerd.co.uk/?p=567

[John Swift]

Hi benni

which board is damaged

is it the KB electronics speed control as in the picture ?

  John

[John Rudd]

I brought my lathe in January this year and I have had a good time with it, but now it's dead. 

Saw, if you bought it January this year surely it is still under warranty?If your supplier cant help or refuses to help, then hopefully we can sort you out....but you should try him first before attempting a repair

I you can answer the question John Swift posed re the board it will help..Also if you can post up a picture of the board that is burnt...

[saw]

Thanks every on for nice comments, I feel that I have very fine friends here. .
Stilldrillin: I have follow you're tree, but it's not the same...
John Swift: I am unsure, there is part that are similar to the link you give me.
craynerd: Total dead, nothing. If I tried to turn the lathe on then disappear all electricity at home.
John Rudd: Yes I have talked to my supplier, and he will see what to do.
This is some photos of my board:
 
When I talked to my supplier, he told me that it was a chance that he had the whole controll panel, if so I'm in haven. 
 
 

[John Rudd]

Looks like a KBIC controller....I'd be surprised if it was faulty, they are usually pretty reliable..

But if your supplier comes across with a spare then thats a good result I'd say...

Even better would be if you got the whole lot and you got to keep the other parts..we could look to repairing the damage, then you may have spares for the future

[John Swift]

Hi Benni,

that's great , a replacement is the best solution

your  control board is a later version of the one in my picture

the surface mount components are more difficult to replace your self

   lets hope it's not too long before your using the lathe again

         John

PS
looking at the wiring diagram
it looks like there is an error with the connections to the forward / reverse switch

take lots of pictures before you disconnect the old control

[pete3000]

Looking at the pictures you posted, I spotted a couple of potential points to look at. The red block top left is a double pole switch? em stop red button.
The blue wire shouldn't be floating it should possibly be connected opposite the brown. on the tab, perhaps the spade terminal has gone missing. I can't see enough to make sure but the mains should come in on flex brown= live, blue=neutral then enter switch.
live and neutral then leave the switch on two white wires? before going to the fuse and mains neon indicator. There is a split of wires covered in tape by the look of it with a live and neutral going to each pcb. This needs investigating to verify the mains supply. If the blue is floating and is touching or shorting to the case (earth) it will trip any rcd you have in the circuit in the house.

The other point is the pcb with the 14 pin chip looks to have a solder splash on the board at the bottom end of the chip? again can't really see.

The function of the two boards is quite simple,
the orange blue wires board is the start stop relay and a transformer to reduce 120v or 240v to the dc motor maximum voltage.
The other board is a pwm speed controller to generate pulsed dc from 0 to maximum duty cyle for the motor. This is done with the potentiometer and a pwm circuit which drives fet transistors. Reversing is done with the direction switch, which reverses the voltage to the motor.

Sorry if this is confusing, the good news is that it is very unlikley that the lathe is scrap unless the dc motor is burned out.
don't lose hope.

Do this in stages with other components isolated. Get the chap who knows to make sure the mains is safe and intact and then to put a meter across the motor + and - wire and take a reading. If it looks good you could try a powersupply or battery with a fuse to see if the motor will run at all. If this is all ok then the boards are next.

Start with the voltage dropper board and see if voltage is present on green wires may be ac/dc can't see a rectifier anywhere.
Then onto the pwm board. Get a replacement

[saw]

pete3000:

The blue wire shouldn't be floating

That happend when I tryed to make some picture as good as possible.
In a few day I will have a new controll box, and then I hope that my problem will be over. 
Thanks everyone for nice comments.

[saw]

Yesterday I'll got my new controll box and on the evening me and my son i law install it, thinking that this would be easey... .
No no no still problem, the fuse breakes all the time. . We have no idea what so ever what to do next, I'm thinking to by myself a new one..
It's sad time here in Sweden 

[John Swift]

Hi Benni ,

test it again with the A- and A+ wires unplugged from the KB Electronics board

if that doesn't blow the fuse
try again with the A- and A+ wires connected again
 and the motor unplugged from the other board with the transformer

if the fuse is OK this time
 you could have a faulty motor or a short in the motor cable

  John

[sub-xtx]

It seems there is a splash in the board, what is it?

[saw]

sub-xtx: I saw it now, as you pointed out, it was a piece of solder. There I have not been and soldered.
John Swift: I have not yet tested A- and A  wires unplugged, but we have tested   the motor unplugged, and still the fuse breaks.
I am very thankfull for all of you advice but right now it seams very hopless.    .

[Stilldrillin]

I am very thankfull for all of you advice but right now it seams very hopless.    .

NOT hopeless Benni!              Don't give up hope.......... 

You/ we haven't found the answer, yet! 

It will be found. Soon!   

David D

[sub-xtx]

You can try to disconnect main transformer and look for correct AC output. If you have a short in the trasformer, home energy drops.
I think you have the problem before entering the logic board.

[andyf]

Benni, I think you need to isolate the problem. Take care with these tests 

Find a 5K potentiometer. Take the new KB board out of the lathe and connect up the potentiometer as shown on the diagram on page 4 here http://www.kbelectronics.com/manuals/kbic_manual.pdf .
Your board will not have the fuse shown on the left of the diagram.
Connect a 230V lamp (an old filament one, not a modern low energy type) to the A+ and A- terminals. Connect the L1 and L2 terminals to the mains, and see if the lamp will brighten and dim as you turn the potentiometer. If it does, then the KB board is OK.

Next, disconnect the lamp and connect your motor direct to A+ and A-. See if it will speed up as you turn the pot. If it does, then the motor and the cable to it are OK.

If those two tests work, then the problem must lie in the other board with the relay on it, in the switches (don't forget any safety interlock switches such as the one on the chuck guard) or in the wiring which connects everything together.

Andy

[saw]

Now I have tried  A- and A  wires unplugged and of course the motor unplugged, result...my whole department went black 
It's like I wrote from the very beginning, my lathe is dead 

[AdeV]

OK - I don't know your model of lathe, but that just means the fault is in front of everything you've unplugged. i.e. the motor & whatever board A+ and A- go to, are OK (probably...), the fault is on whatever is still plugged in. So the next task is to find something else to unplug - can you unplug the board leaving the transformer plugged in? If the transformer is shorted, it'll still blow your RCD. If not, then the fault is on the board you just unplugged and it's time to go find it...

[John Swift]

Hi Benni ,

disconnecting the A- and A+ wires would only prove you had a fault in the motor or the DC wiring to it

if you unplug the L1 and L2 wires from the KB electronics speed control board
can test the relay and tacho powersupply board , you need to ensure the L1 and L2 wires are insulate

is it possible for you to post  pictures of both sides of the board with the transformer and relay
it will help to work out exactly the function of all the wires in the wiring diagram you have

from pictures of the board in another version of your lathe without the tacho
I've drawn the circuit that will be similar to your board but without the transformer and 5V supply circuit

the switch on the speed control potentiometer is closed with the control fully anti clockwise  (minimum speed)
once the relay is energised , the contact in parallel with the switch maintains the power when
you increase the speed

with the power switched off the second relay contact connects a 27 ohm resistor across the motor
to reduce the speed quickly
with the power on ,the relay contact connects the motor to the KB speed control DC output
 via the forward / reverse switch

 John

[saw]

Hi John.
Here is photo as you wanted
 

As you can see the connections to the motor is unconnected, I hope that this can help