mileospart

Sorry about the schematics, I found them in jpg format so it did not make any difference. Here is another one, to me at least is readable when I zoom it. Tomorrow I will try to change the 10 ohm resistor and I hope I will have positive results. If someone also could tell me some info about the T2 power transformer and the TA ferrite current transformer to be able to search for them just in case, I would really appreciate it. Thanks again :)

Thank you for your super fast respond Hero999. I found another one more readable I hope but still on jpg and I transformed it to png. Unfortunatelly where I am now I dont have my osciloscope with me and I tried to measure it with a multimeter hopeing that I would see something, but I guess I am wrong on that :-\ I measured the DC voltage and it seems normal to me, around 300VDC after the capacitors of the brigde and 12 VDC supply after the regulator. I checked also all the power mosfets, diodes, resistors and capacitors and the relay and the only damage I found is the 10ohm resistor after the TR2 power transformer. The weird thing is that a while before I measured the voltage on the output of the welder and I see 15VDC. I searched a little on the web and I found that the electronic welders give on the output a low voltage less than 50 Volts so if this is true 15 VDC should be normal I guess. So I guess it must be a current control issue. I also read somewhere that the currect is controled throught the small ferrite current transformer TA, thats why my attention fell on the part from the TA till the output.

Hello everyone, I have an electronic welder of 200A from electrical olympios (a very similar circuit is attached on this post). Lately when I switch on the power, it seems that everything works fine but when I try to weld a metal nothing happens. I checked the components one by one (even the power mosfets) and they seem ok but I measure 0 Volts on the input of the T2 transformer and the 10 ohm resistor next to it seems also damaged. So I believe that if I would replace TA, T2 and the 10 ohm resistor with the 4.7nf capacitor that would maybe fix the problem. The problem is that I am a newbee electronic engineer and I do not have a great experience yet and because the device is old, the codes of these components are not visible any more so I do not know their values and what to search and order. Could someone help me or correct me on that? PS: Sorry if my English are very bad ;D Thanks in advance