[Solved] KEMPPI Minarc 150 welder - green ON diode and relay not activating

After turning on the welder, the green ON diode does not light up, the relay on the main board does not turn on. Is there any "frequent" fault of this welder for such symptoms? I wanted to draw a fragment of the diagram responsible for the power supply and control of the relay, but the board is made in such a technology that you can hardly see the paths, a nightmare. I am asking for suggestions, possibly a motherboard diagram.

I have just dismantled two of them for repair, previously also repaired. In one of them 5 SGW50N60HS (Infineon) transistors fell. There is a very good service on the electrode. The previous failure is the above-mentioned transistors and the MUR460 diode and the burned path.
In general, welding machines are easy to repair.
I've had such cases.

I also have a question for experts in welding: can the 50n60 transistor (as it sits in it) replace the IRG4PC50W? Ic of the latter is smaller, but they go over 3 ie V4, V5, V6 and V8, V9, V10.
If someone used substitutes, what kind?

I use these IRGs as replacements successfully.

I'll check today. One I can devote to experience, I have some used IRGs. If it starts, I will take measurements, compare it with the service center and describe it.

The welder works on IRG transistors, I do not know how it will be with current efficiency during longer welding, but the welder will test it. For me, the matter is settled.

IRG4PC50W transistors are also used in these welding machines at the factory, so nothing prevents you from using them.

I am looking for a schematic of the A001 control module and the value of the R9 resistor on the motherboard.
If one of my friends could help, it would be very nice

The basis is that the large electrolytic capacitors have approx. 300 V. If there is none, it will not start.

R9 is 100 k? 1 or 2W.

Thanks, the calculations gave me 68 k?, which is very close. Overall, it is not a critical value, because the PWM driver starts correctly in the voltage range of 11 ÷ 16 V, so the value of 100 k? is just right
Now we need a diagram of the A001 control module.
Maybe someone will find in their resources?

What value should the resistor R37 have?

The resistor housing is slightly cracked, but not blown apart, just as if it was broken from tightening the heat sink too much. So I wonder if I should replace it.

If this is the resistor screwed to the heat sink with the output diodes, it has 10 ohms.

If anyone knows, please provide the symbols of N2 and N3.




Found.
As if someone was looking for posterity.

N2 - PWM UC2844b chip
N3 and N4 - LM239 comparator

Does anyone have a Schema from electronics to Kemppi Minarc 150 precisely for A001 CARD

I have a problem on a small card A001. The card receives power from the large plates 23V.
I have replaced the N1 and N2. Still does not turn and do not include the green light... Input voltage on N1 varies from 10 to 15V

When you remove the N2 2844, the voltage does not vary.

AFTER REPLACING NEW N2 can vary VOLTAGE.

Check diodes and transistors on N2 with oscilloscope, square wave on 6th pin. The green diode will light up only when the main transformer starts and gives the second voltage to the A001 board.

I found t2 tr stopped where I can find this song? Part No. 150622/0927 SIRIO .thanks!

Another version of this diagram drawn by me. Can help.

this is the position of the piece

Dear good day
I tell you, I am repairing a MINARC150 soldering equipment, which had the IGBT IRG4PC50W in short circuit.
Replace them at 6 IGBTs and check diodes and gate resistors, all OK.
I turn on the equipment, measure voltage at terminals and it is equal to 85 vdc.
I start to weld and as soon as I end up the electrode the IGBTs are short-circuited again.
My query is: if it ever happened to you and how to fix it. If they have any recommendation or indication to take into account.
From already thank you very much.

The answer after years, but it may be useful to someone:

0. The welding machine has voltages that are dangerous to humans, a charged capacitor can damage the service technician!

If you used transistors really as they should be:
1. I used a different 300 W and 50 A for Minarc 140; 600 V or 650 V after repairs shaved even 4 in the welding shop.
2. IGBTs have it that if the gate is in the air for us (micro second), it breaks through the collector-emitter, so the path to the gate is thin, like an old welder, it's a flexible cable parallel to the path - the path may have a microcrack you hit the welder and bang the IGBT
3. There is an overvoltage varistor and capacitors on the output - you detach the electrode, pulse on the primary IGBT bach
4. All the same IGBT
5. Check the quality of current connections at the output after repair, where it does not make good contact, it heats up there and will make a hole.
6. The output diodes must be efficient and of appropriate quality.

Hi, i have a similar problem, i have two machines that working but can’t deliver the full power, I already change the igbts and check the output diodes but the machine still the same. Any suggestions??? Thanks

Short circuit on the choke. About 20A less. L001 in the diagram.

Somebody can help with r62 resistor value kempi minarc 150

R62 it is 1 ohm resistor rated at 1 W or 2 W. Do you have a green control board? Can you take a close up to it? thnx.

I warmly welcome
I have a damaged welder after mechanical damage (fell).
The transformer core has broken.
I assembled the core, poured epoxy glue, replaced the IGBT and the bridge. The welder was operating normally.

After some time, the welding machine stopped working, the green LED on A001 lights up for about 10 seconds and goes out, the fan turns on for a moment.
PTC R23 and R30 heat up, the relay does not switch on. By the time the PTCs warm up, the voltage across the electrolytic capacitors is around 270V.
After turning on the PTC, the voltage is about 130 V.

He has something to do with me, but I have no idea what. IGBT are not short-circuited. Maybe I will desolder them if the gates work ok.

Or maybe someone had something similar?
Please give me a hint.

I will add that I replaced A001 and it did not help.

Hello, I solved the problem.
The LM317 was damaged, giving too much voltage, which resulted in a damaged relay coil.

>>16908312
C56 is not in this plane, and what component code does N4 have?