ESAB em215ic part identification

[11Hopeful]

This welder does not power on and looking at a thermal image I'm seeing the hotspot on R79. The cap comes off pretty easily and under it is a disc made of some type of conductive material. Does anyone know what this part is and what is it's function? How much current should I be measuring for at this component?

Any help would be wonderful.

Regards,
Bryan

[smithdoor]

Did you check the voltage coming out transformer in photo.

Most time with electronics it is transformer or rectifier that dies.

Dave

This welder does not power on and looking at a thermal image I'm seeing the hotspot on R79. The cap comes off pretty easily and under it is a disc made of some type of conductive material. Does anyone know what this part is and what is it's function? How much current should I be measuring for at this component?

Any help would be wonderful.

Regards,
Bryan

[11Hopeful]

I'm not sure if power has reached the transformer at this point? Does ESAB provide a more in depth manual for this?

Did you check the voltage coming out transformer in photo.

Most time with electronics it is transformer or rectifier that dies.

Dave

[11Hopeful]

A couple of images for reference.

[mrmikey]

Could it be a rectifier disc of some type?.......Mike

[11Hopeful]

I know it's shorting out and not allowing voltage to go beyond that point. Does anyone have a manual?

[lugweld]

Here's a service manual link that might help. You don't show what kind of board it is. Hard to help. Need a bigger frame of reference.
https://www.manualslib.com/manual/12...page=61#manual

[lugweld]

My guess is that it is a fuse.

[11Hopeful]

Here's a service manual link that might help. You don't show what kind of board it is. Hard to help. Need a bigger frame of reference.
https://www.manualslib.com/manual/12...page=61#manual

Large photos of board.

[Jack Ryan]

It appears to be a positive temperature coefficient thermistor - part of the inrush limiting circuit.

Jack

[11Hopeful]

I think you are on the right track Jack. I'm contemplating taking the disc out and testing to see if I can get it to power up.

[N2 Welding]

Have you tried a continuity test on that disk? If it is temp controlled and has opened from high temps, you might be able to get it to close again by letting it sit in the freezer for a little while like say a half hour or so. I had to do that a couple of times with a microwave after baking potatoes in the nuker.

[52 Ford]

Have you tried a continuity test on that disk? If it is temp controlled and has opened from high temps, you might be able to get it to close again by letting it sit in the freezer for a little while like say a half hour or so. I had to do that a couple of times with a microwave after baking potatoes in the nuker.

Freezing electronics is a great way to troubleshoot bad components. Canned air turned upside down works pretty well.

One of my old cell phones has a shattered screen. To make the phone cut on I have to stick it in the freezer for about half an hour.

Sent from my Lincoln Buzzbox using Tapatalk

[N2 Welding]

I don't buy canned air. I just dial down the psi on the compressor but thats a neat trick.

[11Hopeful]

I tried the freezer trick unfortunately continuity reading is still zero

[lugweld]

My understanding is that on those things is that the continuity increases as heat goes up. That would be related to turning on a switch or sensor at a particular temp.

[11Hopeful]

Anyone know what might happen if I remove the ptc thermistor and plug the machine into an outlet?

[Jack Ryan]

My understanding is that on those things is that the continuity increases as heat goes up. That would be related to turning on a switch or sensor at a particular temp.

That's right. This one limits current until it heats up and then the relay operates. It is part of the inrush suppression circuit.

Jack

[Jack Ryan]

Anyone know what might happen if I remove the ptc thermistor and plug the machine into an outlet?

Probably not.

The thermistor may be collateral damage, not the fault itself. There is a power up procedure given in the service manual.

Examine unit for any visible signs of damage.
In order to prevent tripping wall fuses and/or causing damage to the unit when power is applied, it is recommended
that the following components be checked prior to connecting unit to mains power:


1 MAINS POWER CABLE INPUT POWER CABLE/PLUG
2 SW1 ON/OFF SWITCH
3 CB1 CIRCUIT BREAKER
4 VR1 VARISTOR on POWER PCB2
5 BR1/BR2 BRIDGE RECTIFIERS on POWER PCB2
6 PTC1/RY1 PTC1 (R79) & INRUSH RELAY (RY1) contacts in parallel on POWER PCB2
7 D49 & D50 DIODES on POWER PCB2
8 Q19 & Q21 PFC TRANSISTORS on POWER PCB2
9 C35-3 WORKING CAPACITORS on POWER PCB2
10 Q3,4,6,7 SWITCHING TRANSISTORS on POWER PCB2

Without the thermistor, the mains CB will probably trip - even if everything in the machine was working.

Be mindful of the voltages on that board - you may end up with a fault yourself.

Jack

[11Hopeful]

Failed test on # 8.

[11Hopeful]

I checked what I think are the Mosfets? I see 8 of them on the power board. Are all Mosfet legs when starting from left to right prongs in this order (gate, drain, source)?
If so, I put a multimeter neg lead to the source and pos lead to drain on the diode test and found 2 that are shorting out.

[11Hopeful]

I had mentioned there are what I think are 8 mosfets but there is 2 that I can only see 2 legs sticking through the board.
I think they are also mosfets but could someone clarify?

[11Hopeful]

I need to see if other components in the surround area were also damaged. Does anyone know what those black objects are?