H150-1 not working

[Philip May]

An engineers next to where I work gave me their welder to look at to see if it can be repaired. They had taken it to where the bought it and was told it was not repairable. They had been using it on a generator at the time. The 10uF capacitor on the main board had blown up,so I replaced it still no go. There is power to the main board but not been able to trace it very far. Is it repairable or scrap.

 

[500e]

Bit more info + pic if possable

 

[Philip May]

Serial no is 318-1807--006
When plugged in there is power to the main board but nothing else. Nothing on the front panel works and no power to the leads.The 10uF capacitor I have put in is the same make as the original.



What other information do you need.

 

[the snooper]

things to look at was the welder recomended to be used on a generator and if so was the generator uto spec for the machine did it have an avr to supply a constant safe voltage ?
i would imagine it has taken out 1 or more ic on the psu board that feeds the display and so on

 

[Philip May]

It was only a 3.5kva generator and the welder was at full amps. They said it was quite a loud bang

 

[the snooper]

It was only a 3.5kva generator and the welder was at full amps. They said it was quite a loud bang

that was way too small as soon as they struck an arc the generator would had slowed down considerably altering the output frequency and voltage causing the damage it may have several parts gone

 

[Philip May]

I have had another look at this welder. The tracks around the capacitor look a bit suspect but no other obvious faults . I have tried to trace them not much luck is the main board 2 sided or multiple layers. Have looked on the web page for a circuit diagrams but can only find a parts list. I saw the owner today and he said they normally use it on a 6Kva generator but that was in for repair only having a bracket to weld on though it would do the job.I have been at my sons for several day helping him out so no time to check out the welder.

 

[Brad93]

3.5kva machine won't have AVR. That welder will be FUBAR. New boards needed.

 

[HughF]

The avr is there to stop the voltage spikes when the generator comes off-load. This is the point when the input voltage to the welder can spike above the voltage rating of the input bridge rectifiers and the magic smoke comes out... It's never happened to any of my cheapanese inverter machines running from any of my generators, 4-5kw mostly (only the 22kva has an avr)...

Low voltage/low frequency brownout situations will not damage a switch mode power supply...

If this is a half decent inverter then the input stage will consist of a pfc circuit followed by the input bridge. If the input bridge looks okay then suspect the pfc circuit.

 

[G473L]

sir can you help me by showing or telling about the size of the two capacitors that I circled in the picture