Jasic 200P AC/DC Repair

[paulo1974]

i think they were on a older board. that bord has a broken leg mosfet or igbt.

 

[Justin K]

Yes, that is the old board which I have replaced with a new one now.

 

[Jan-DIY]

On a standard inverter welder the first part is the rectification of the ac to dc. there should be two 24v outputs one for the fan other for the gas valve. As for the 24vdc valve unplug and give a 24vdc or less 20vdc should suffice to hear the valve click. On one image that you post i saw some burn mark near the fast diodes (converting the high frequency ac to dc)

As you can see in diagrams fans and also solenoid is driving by mains voltage.

 

[Jan-DIY]

Any success?

 

[DSR]

I have a 19.2 reading from one side of the fuse to the other and no readings from the 3 x PTC, visually they look fine. Sorry for my naivety, but I'm checking the resistance from one side to the other with the multi meter, without any power on, is this correct? The DC Link relay I cannot get any resistance reading from either, using the two pins on the underside of the board.

Are you able to circle the "outmost right connector between yellow and black. I mean the 4pin shell with 3 wires on the other side".

Hi Justin,

what did you mean when you said from "one side of the fuse to the other", was this the voltage measured across the fuse or at both ends of the fuse with respect to the 0V (or other) power rail ?


D

 

[Jan-DIY]

Doesn’t matter as long as he get voltage on DC bus.
Because he is obviously not very familiar I ask to weld on stick.
This will show if DC link is in business or not.

 

[paulo1974]

I suggest making a gas valve box that can be started when you press the trigger.

 

[Jan-DIY]

Then he is in struggle with pre and postflow.
I would have a closer look at mosfet, zdiode and relais.

 

[paulo1974]

Then he is in struggle with pre and postflow.

there is a simple way to add pre and pos flow on the external gas valve box.

 

[Jan-DIY]

there is a simple way to add pre and pos flow on the external gas valve box.

Please share your information here.

 

[paulo1974]

i have to ask how he did it but as i see the pcb it was 3 relays with 2 potenciometers. i need to check this

 

[Jan-DIY]

Did you ever dealt with high voltage ignition?
I do and can only speak for myself that it will kick everything out of business if not doing properly.

 

[paulo1974]

The gas valve box is isolated from the high frequency. They only use the signal from the torch trigger.

 

[DSR]

Did you ever dealt with high voltage ignition?
I do and can only speak for myself that it will kick everything out of business if not doing properly.

I fried my 30 year old DMM because I stupidly forgot to disconnect the HF start . No second chances.

 

[Jan-DIY]

Any news on here?