CUT50 board connections?

[skotl]

I've made a board aping the CUT40 relay operation switch, so now the relay clicks in after startup and the machine runs without the thermistor switching off. However, I have no cutting power.

The spark gap sparks as long as the torch button is pressed, and air comes out at the recommended pressure as the valve solenoid actuates. There is an arc from the torch to the workpiece but no great flames, and no cutting, just some slight pitting of the material. I have a selection of new consumables and it doesn't work with any combination of them.

I've never used a plasma cutter before, so I'm not sure what I should be expecting. I wonder if there is an insufficient DC potential to create the plasma, but I have 50V between the torch and clamp. The videos certainly suggest an easy cutting action but I'm not sure what to try next.

It's very obvious when it's working so there's clearly something still off. Are you able to tell what impact, if any, turning the amps knob up makes? Perhaps the logic around that area is faulty.

 

[Dragnet]

It seems to have zero effect. The board I'm using is a replacement from a similar but not the same model. The three pins of the current knob attach to a socket connected to the same pin 6 of the main control board, but there is no attachment point for the digital readout. I'm considering making that up on another breakout board instead. I haven't investigated the control board, but the components between the 24V supply and the central wiper of that potentiometer are very similar, despite the lack of readout. However, there is no variation in control voltage signal to pin 6, which I can't work out. I assumed that the potentiometer provided some variation to that pin, but perhaps I haven't got the circuit sorted yet.

Is it the kind of performance you would expect from having the thing set too low? I have nothing to compare it to except videos of people cutting metal like butter!

 

[skotl]

It seems to have zero effect. The board I'm using is a replacement from a similar but not the same model. The three pins of the current knob attach to a socket connected to the same pin 6 of the main control board, but there is no attachment point for the digital readout. I'm considering making that up on another breakout board instead. I haven't investigated the control board, but the components between the 24V supply and the central wiper of that potentiometer are very similar, despite the lack of readout. However, there is no variation in control voltage signal to pin 6, which I can't work out. I assumed that the potentiometer provided some variation to that pin, but perhaps I haven't got the circuit sorted yet.

Is it the kind of performance you would expect from having the thing set too low? I have nothing to compare it to except videos of people cutting metal like butter!

Yeah - if set too low then it just acts like a mini / useless arc welder.
So could be the control logic but could equally be the high-power side

 

[EBME2]

I found this manual quite useful to work out what some of the modules do. It is for a BOC Tig 185 but gives the pin outs of the various add on modules that stand up from the PCBs as the boards are fairly similar, the circuit diagram also has quite a lot of similarity.

https://www.manualslib.com/manual/924827/Boc-Smootharc-Tig-185-Dc.html

 

[Dragnet]

That's a brilliant resource, EBME2 - I wonder if the board I was given with the unit is actually from a TIG welder? It shouldn't make much difference as it's just generating that high frequency, but I'll follow through on the diagrams and have a look. It seems from a cursory glance to be very similar in layout. Probably these units are just Chinese clones of ones being made in factories for known brands.

 

[aminedev]

one photo can help me , my cut50 get burned , this toshiba mosfet number 1 exploded and destroy the board front of it, please help me i need to know the value of 4 resistors of board number 2

this is the resistors i need to know there values , please if any one have the cut50 please make a clear photo to this small board its on top of machine

please help me to repair it back to work

 

[EBME2]

Hi

My guess is these are made by several manufacturers who use different layouts and even components. Not sure if it helps but see

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Riland/Jasic WS LGK ZX7 200 Inverter welding machine circuit board Auxiliary board, switching power supply board - Price history & Review | AliExpress Seller

alitools.io

I’ll try and take the lid off mine sometime but too hot at the moment to be doing such things. It might be a different board in mine.

 

[aminedev]

Hi

My guess is these are made by several manufacturers who use different layouts and even components. Not sure if it helps but see

4.92 $ | Rating 100%

Riland/Jasic WS LGK ZX7 200 Inverter welding machine circuit board Auxiliary board, switching power supply board - Price history & Review | AliExpress Seller

alitools.io

I’ll try and take the lid off mine sometime but too hot at the moment to be doing such things. It might be a different board in mine.

thank you for your replay , i found this board but im not sure if it will do the same job because its look deferrent and also have less items inside. (also its take long time to recive it , im in morocco, need about 2 month)
please if can a memebre take a photo of this board inside the cut50 will help me so much

 

[gaz1]

i have the same board and machine just cant get to it at the moment

 

[aminedev]

i have the same board and machine just cant get to it at the moment

View attachment 356302View attachment 356303

this is the board im talking about

 

[aminedev]

can any memebre help me to take a photo of this board on cut 50

 

[gaz1]

have a little patence will you for a new member

for start off your asking members to take there machines apart and then take a photo of a board that is hard to photo in the first place never mind bend the resistors to get a better photo of this board for you

some of us work and can only get to there machines at the weekend

 

[aminedev]

I am patient and I wish someone help me
me to my work stop and I have nothing to do just trying to repair my machine, but without knowing the correct value is like impossible to fix it
thank you for understanding

 

[gaz1]

once i could get the wood doors out of the shed without the rain hitting them
that means i cannot get into the shed at the moment so needed dry days to get what you was wanting

but heres your photos of that board for you as my cut50 has been powered down for a long while so isnt holding any charge within it


you can download and zoom in with my photos right click open in new tab on the pic then click the + sign on photo and download as full image by right clicking save image as

i read 2r2 for the 4 ressistors in that pack area

ive done electronics so have the passes id advise to check the surronding ressistors and capacitors and transistors with what you have theres a good chance something else may have been taken out as well

 

[gaz1]

anyway welcome to the forums

your more than welcome to join in on here we all have something to offer one way or another

im a mixed builder and even i have some welding gear and alot of other gear as well to deal with

im on these forums helping out others

so like you see plenty of other info on here to be had and enjoyed

 

[aminedev]

ooh thank you so much yes 4 of 2r2 resistors, straight and parallel, are like one 2r2
yes I'm not sure about the other capacitors and Zener diode and resistors I try to test it maybe it's okay but I'm not sure, I will try my chance
and I will post my repaired board and what I have done.
I'm a developer and I have the pleasure to give help with anything Informatique or algorithmique

 

[stonkin9899]

Hello I'm new! I've got a cut 50, for months I've been trying to work out what's wrong with it. Plug it in. Nothing happens. I've found the top capacitor was split, replaced that but now I believe I have a short somewhere. I get nothing on screen but the bottom green transistor gets really hot. If I unplug the connection to the top board from the bottom left board the fan runs but nothing else. If I plug it back in I get all the pops and bangs! I'm lost! Anyone seen anything like this it's driving me insane only used it 3 times before it went pop! Out of warranty of course.. the picture attached shows my only other clue and I've put that (c15) back in place now

 

[gaz1]

im not surprised with all those metal bits in there

theres enough on that boards pcb alone to cause enough damage

 

[stonkin9899]

im not surprised with all those metal bits in there

theres enough on that boards pcb alone to cause enough damage

It's dust, been sat for months

 

[gaz1]

yes its dust but it also tells me alot that you have a grinder dust issue where some tools like the plasma and other digital machines should be placed into a seperate room or cupboard where dust isnt a problem

welding dust is known for destroying parts more so with digital equipment

anyway back to your issue first off thanks for the first pic but i couldnt even tell you what board that is from or what part its from not enough pic of the board first

note here you need more pics than what you might think as much as have you tested for power after the plug or has the fuse blown or has a connector underneath the pcb board blown

it would help if you ry to explain what you have done to get to this issue