Kraft & Dele IGBT250 Welder: Switch Lit, No Fan or Display, Fuse Location?

Question

Hi,
This is the situation: patient Kraft & dele inverter welder. Symptom: does not start, the fan does not spin, does not display the current. Only the switch is lit when it is turned on. The switch is checked, lets go on. I can't see the fuse anywhere. Where to look What to check? Is it something simpler or rather direct to the website? I would like to point out right away that I do not have an oscilloscope or deeper electronic knowledge.

skalsky5000 · Answer

Check the board with the bridge, the white resistor and the relay on the capacitors should be ~ 320V DC.

tbilski · Answer

Thanks. I checked on all 3 capacitors it is ok 340V. Anything else to diagnose?

master250 · Answer

Check that 330V DC voltage reaches the top plate.
You probably have a damaged 24V DC auxiliary converter. If the voltage of 330 reaches the upper board, check your voltage to ground on the power supply of the UC3845 converter controller.

tbilski · Answer

Tension is coming up - I checked

. If you help me find this inverter driver, I will measure it soon.
Looking through the entire PCB at the top, I found two capacitors in the vicinity of which some leakage can be seen, of course quite dry. I don't know if this is normal and if it was like that from the beginning, unfortunately. Is it somehow verified?

stasiekb100 · Answer

In such a model, the terminals of the primary winding of the auxiliary transformer burn out. Possibly a current measurement resistor of the primary winding of the auxiliary transformer. I do better without removing the auxiliary transformer.

master250 · Answer

The driver is an 8 vertical chip mounted closest to the yellow pulse transformer of the auxiliary converter.

tbilski · Answer

Will this be the 8 pin scalak? Vcc will be on pin 1? That with mass?

stasiekb100 · Answer

Have more something like that you have there.

tbilski · Answer

@ stasiekb100 Thanks for the diagram, but you overestimate my possibilities I will handle the measure, but I will not undertake the interpretation of the scheme and reference it to real ground without guidance .

Pawu0206 · Answer

Hello. The topic is a bit unearthed, I have an identical problem with the fact that the board is a bit different. Only the switch lights up when the power is connected. There is no voltage on the capacitors and also no voltage on the 24v relay. Does anyone have a diagram of this version specifically? Might Scalak be damaged? Oh, I would like to add that the welder stopped working after it fell over. I thought that some wire broke, but 230v is reaching the board.

Krzysztof Reszka · Answer

What do you mean? If it concerns another problem, create a new topic.

Pawu0206 · Answer

My point is that although it is the same model, the igbt250 differs in interior. And the problem with the device is exactly the same. Analyzing the posts of my colleagues above, I came to the fact that I do not have voltage on the capacitors. And in the above posts it was. That's why I'm looking for tips on what to look for.

stasiekb100 · Answer

Softstarter resistor, approximately 50 ohms, power 5 W or greater.

Pawu0206 · Answer

Will it be a smd resistor or a regular one? Because I am looking and I cannot track. Will it be soft start in these attached plates?

star_vad · Answer

Hello. Measure the voltage across the capacitors and everything becomes clear. A soft start on this board is - the charge of the filter capacitors passes through the position signal (green around the relay), then a small beep on demand starts, then the relay turns on and the posistor closes the contacts. In the meantime, you don't know if you have a broken switch or positron or if your low power supply is not working. Also check the IGBT for serviceability. Not exactly smd

Raku025 · Answer

Hello, I have a question, on this board, the photos of which were sent by my friend Pawu, what are the two precise potentiometers sealed, located near the bone connecting the display and current setting potentiometers

Kraft & Dele IGBT250 Welder: Switch Lit, No Fan or Display, Fuse Location?

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